Yes, you can group your friends and just share with some of them, but who has time for that?
I'm even hesitant to write anything in semi-open groups as I'm not sure if what I write will show up on my friends wall. It's not like what I'm writing is extreme or private, I just don't need it to be actively shared with all my "friends.
It's interesting that facebook got it initially right, and NEVER implemented 'who's viewed your profile/picture' - as they know that this (possibility of others seeing our actions) would greatly reduce our actions/viewing (us fearing it being visible).
WHILE now, they're not getting it right and publish our actions (likes/comments) like a mad spammer.
It looks like they crossed the border while playing with our curiosity what-others-do, but forgotten that this means, that our actions need to be revealed to others also which will make us reluctant the moment we understand implications.
Snow ball effect to come?
In this regard, Facebook has always seemed like it wanted people to overshare with everybody (it's been proven with its blunders on the privacy front). Now the same overload is causing fatigue among its users (at least to some extent).
I'm frustrated that Google+ has been stagnant like a beta service without new features or even addressing usability issues to make it better for years now (vanity URLs for groups/users - still no; changing group privacy after creation - still no; and many other annoyances).
That's exactly how I feel. Facebook shows to me, to the right side of the screen, a feed of all the comments and likes my friends make everywhere on the site, even on pages I don't like or on walls of people who are not my friends. It's like some kind of "spy mode" which makes me reluctant to comment anywhere (what if my friends will read it?).
Gotta love addiction optimization, one of the many wonderful sciences the modern age has brought us. See also: drop rate optimization in games.
Like you, I found myself doing the "quick scroll through" until I finally deactivated my account.