I totally agree. I've also noticed a drastic shift with the content I consume moving from mainly long form and short. I've actually started to try to move that back a bit. But one thing I've noticed is that long form has suffered as well and seems to be a little cheaper and poorer quality (on the whole) than I remembered. I wonder if authors feel pressure to compete with bloggers and this plays out to some extent in the quality of their work.
Hmm. Regarding long form, there has always been so many bad bad bad terrible books out there, and more every day. For me it's always been about selecting the great reads that are out there. There will always be dissertations launching books, and niche experts and popularizers putting the time in. But I just think that short form lends itself to dumbing down in many of the ways it is packaged for us. It is packaged to live alongside advertisements and mingles with that. Then there is the internet that coined the term link-bait. At least I'm not the only one :) I've made an effort to read more, longer works over the past couple years as well.