What I meant critical thinking was pretty bad in the past, and it's pretty bad right now (albeit relatively better).
The big change is the outreach of misinformation.
In the past, it was a million separated islands, connected through mostly one-way data streams (books, radio, television). Today, the vast majority of data streams are two-way, because of social media. The million islands became one giant fuzzy continent - and bad critical thinking people now unite and gain power that way.
Something would have become viral in days or weeks, now it becomes viral in minutes. Furthermore, if something was stupid or totally false, there was more responsibility from those responsible with disseminating it (through the one-way channels mentioned above), and more often than not it never went beyond some tabloids. Today, there is no such filter. Unless you publish something truly and very obviously illegal, social media companies are happy to publish it, especially if you give them money and turn it into an ad.
I'm sure there were tinfoil hatters in the past who believed the Earth was flat or that birds don't exist and are instead spying machines, but those cuckoo ideas never took flight, since nobody in their right mind would publish those ideas for the world to see. Now you can run those ideas as ads on Facebook for a couple hundred bucks or something, and reach way more people than before, people with questionable at best critical thinking.
