There's so much to like it's hard to pick just one thing.
Most of the likes have already been covered. The history, the challenge of finding something special or a deal. Seeing how other people approach the hobby.
I'm always a bit jealous of the collectors who can put together amazing collections, but I'm also really glad they're out there doing it. Especially if they're willing to show off a bit. (Go for it guys, you really do deserve it

)
I like that there are other people who are ok with approaching cards a bit more technically as well. Coming from collecting stamps and a few coins the fun of looking at the small details has usually seemed missing from cards. Or was until I found this board.
I even like the new stuff. Maybe not all of it, but most of it. Some stuff is just as much of a challenge as prewar, and cheaper. I don't really like that so few care enough to even keep track of the new stuff, but that leaves some puzzles for the guys collecting 30 years or more from now.
Dislikes? Again, mostly covered. The scammers and guys just in it for the money were always around and probably always will be. It's just become a bit harder to tell them apart from the ill-informed.
Maybe the people who aren't open minded about aspects of collecting they don't have an interest in? But that's always been that way too. There are ways of collecting that just haven't caught my interest, but if someone else collects that way that's not such a bad thing.
Steve B