tl;dr? LotRO is a good place to hang out and slow down. If you've got a good gaming rig, the environment is beautiful and if you're a Tolkien fan, you'll (for the most part) love what they've done. It has it's hangups, but they are few and far between.
And now for the longer part:
As an admitted fan of LotRO I have to disagree entirely. If you've *ever* played an MMO in recent times there are *always* going to be "filler" quests as you level up. LotRO certainly has those at lower levels because the entire point of lower levels is to start to learn how to play your class. You do this by killing things. You have quests which ask you to deliver stuff (like rotten pies or the mail) because it introduces you to the surrounding area... which when you're brand new is likely completely foreign.
One thing LotRO offers that continues to deliver is the "Epic" storyline. This is a series of volumes, composed of books, composed of chapters. Each chapter is a quest in an ongoing storyline which weaves in and out of the original LotR story. Naturally, at lower levels the Epic line is also fairly easy... it's another introduction. Sure there are some quests/stories that are not so great, you can't please everyone all the time (don't get me started about the Epic line running around Forochel... blergh!). But there is *a lot* of really good content in LotRO.
Another aspect that keeps me coming back time and again is the world itself. It's very detailed, very "pretty" (even in a bad way in some areas), and very true to the lore of Middle-earth (leaving out the scale-down... I mean who would want to literally walk/ride 30 miles to Bree?).
It certainly has some short-comings, I'll readily admit. The interface is quite dated and very hard to "skin". Turbine is working on this, recently starting to expose lua plugins as they should have done from the get-go (one thing WoW did from the start that was a phenomenal boon to the game). Folks who come from the WoW concept of "grind through everything as fast as possible to get to the end-game" who continue to follow this pattern will not enjoy LotRO. The "end game" is a handful of instances and 3-4 raids. They have recently improved this by going back and making almost all the existing instances (3 and 6 man) available on a scaling level (meaning you head into the Barrow Downs at 65 and it's scaled for 65 instead of the original level 20). They also provide a system called Skirmishes which gives you a soldier NPC that fights with you (several classes available). There are several sets of gear one can obtain which allow you to move into the 12-man raid instances if you desire.
While the "Legendary" item system never really lived up to it's full potential, they've made great strides since it's inception to improve it to a decent state at present.
There's definitely room for improvement. The kinship (guild) tools are pathetic. The housing is at best adequate. The tradeskills are okay. Combat is fairly easy, but still fun. The class divergence is quite well done (which makes it fun to play alts since the playstyle is considerably different across the classes).
In general, it's a fun world if you play a game to enjoy the story, the environment, and the other folks who play. If your enjoyment is leveling as fast as possible and just clicking accept whenever you're offered a quest, it's not really for you. That said, there are a lot of folks who enjoy a change of pace where it's not a rat race to get to the end and then an endless grind to do nothing but improve your gear with cookie cutter skillsets and classes that, in large part, play exactly the same (yes, that was a shot at WoW). I think LotRO will continue to thrive and be successful. Everything we've heard coming out of Turbine since the switch to Free2Play has been positive and, at least on Elendilmir, we continue to see the world fill up in the evening and on weekends.