At least for myself, the situation actually became worse over the past few years, and the symptom is actually quite clear.
Half a century ago, movie theaters were the only place to see a movie. A few decades ago, video set people free to view a movie when they'd like to see it. At first, it took about a year for any recent movie to arrive on video, but during the 1980s and 1990s, this timeframe did drop to just a few weeks.
A little more than a decade ago, DVD started its rise and the movie industry at first did offer mostly old movie titles on DVD. Movies were still being screened for usually 2-4 months in theaters, and released on DVD after at least half a year (for poor movies) and up to 2 years for certain blockbuster movies.
A few years ago, BluRay (BD) started. However, upscaling on recent TVs or BD players does make DVDs look quite good. Not exactly that crisp like a "real" BD, but e.g. for CGI animation, there's no way for casual viewers to tell the difference between DVD and BD without a magnifying glass. Some "softer" upscaling edges are sometimes more pleasant to the eye. So the video- or dvd-like "let's resell the same stuff on different media" business didn't work out that well.
Today, almost no movie does run for more than a month, and DVD/BD sales do start from as low as 6 weeks after the initial theater screening, DVD/BD rental even do start 4 weeks after the initial theater screening. Only major movies do experience the grace of having their DVD/BD released 4 months after initial theater screening. However, just during the initial theater screening, you can find the DVD/BD date by searching for the DVD at Amazon. Am I the only one to see a plot here?
Of course, "recent" DVDs are being sold for about two movie tickets (and after 2-3 years, you'll find some of them being a giveaway in some magazine). Some movies even do debut on DVD/BD first and aren't being offered to movie theaters at all.
Of course, there are three ideas about this symptom:
First idea: the movie industry is likely to say earnings from theater screenings are so poor they're forced to enter the post-screening market that early. And there's also a lot of movie piracy on the internet, where people start downloading screeners very soon, just in order to hold a copy of this movie - so they're offering DVD/BD very soon at low prices to discourage people from doing so. However, this doesn't explain why retail stores do publish DVD release dates that early.
Second idea: the casual viewer does have multiple options for entertainment: movie theaters are just one of them, there are also DVD/BD, video streaming services - and computer games. During the past two decades, computer games went from "written by half a dozen guys" to "multi-million dollar project with more than 60 developers, 100 screen artists and a dozen of sound developers". Games like Batman Arkham City do give such a movie-like impression that people can't decide at first wether they're viewing some split scene or some in-game action - so these games also do offer quite an astonishing level of entertainment as well.
However, everybody's daily time is still limited to 24h and in the end, the "entertainment market" is being sliced into much more pieces than half a century ago.
Those who probably kept a 90% market share "back then" just aren't able to accept they're now only receiving a fraction of what they were used to.
The third idea is simple as well, but needs some explanation: there are multiple branches within the movie industry. One does the theater screening sales, the other cares about the post-screening sales (DVD/BD). Of course, the second one has to follow the first one - otherwise, the second team would kill any potential success of the first team.The theater team is limited by a certain timeframe, while the DVD/BD team literally has a nearly endless amount of time and still benefits from the initial hype and marketing done by the first team.
By some top management view, the post-screen sales are much more interesting, as they're not limited by a certain sales timeframe and there are many ways to further enhance sales by offering some "extended edition", "collectors edition", "plus some plastic miniature edition", "movie and its sequel in one box" or even ""movie and some other related movie one box". Try doing the later with a theater movie - people will see you're nuts. Literally all marketing in order to hype the movie is also being paid by the first team, so the raw figures also point the post-screening team is more valuable.
In order to push their sales, the second team nags and shortens the timeframes of the first team.
At some point, movie viewers don't really care anymore wether they do see the currently hyped movie "now" (e.g. after two weeks of theater screening) or just a couple of weeks later. Hey, DVD/BD is some media being completely unusable for a "must see it now" hype, so once you're shifting from the "must see it now" audience to "I'd just like to watch a movie" audience, you're lost for the hype-based theater screening market.
There are also other issues as well. Theaters force you to see a movie at some awkward time ("movie starts at 2pm, 5pm and 8pm"), but probably most of those times are completely useless to you. Your're working in the office till 5pm, so the "2pm" and "5pm" starting times are useless to you. At 8pm, at least another dozen of different movies do start, so the ticket counters are completely crowded and you do spend half an hour in some waiting line. So either you do take the extra turn of getting your 8pm-tickets during the lunch break, or you spend some weeks waiting for the hype to settle, so the theater will shift the movie to a different screening room, where screenings do start at 7pm. In both cases, "watching a theater movie" is no longer a pleasure, but also has some annoyance.
At this point, you're also no longer accessible to the hype theme: movies became some kind of commodity to you.
However, those smaller screening rooms often do lack the digital projector with the crisp picture, and your actual viewing angle is quite poor in comparison to that 46"-60" screen in your living room. The other idea: wait yet another few weeks for the movie to arrive on DVD/BD. And while you're already waiting - why not wait just a little longer, so the price for the BD drops to the price of todays DVD?
In the end, probably all of those three ideas may apply, and it's just a matter of arguing which is more the case.