When I do check out someone's twitter post (e.g. sanders, or dan harmon) then the replies are total junk. HN has tons of interesting people replying, twitter posts have tons of junk/spam as replies.

How is the user supposed to know how many people is a good amount to follow? I think that is Twitter's problem, not the user's.

Or too many noisy people. Some folks can literally drown your timeline.

The problem is that I want to hear x's opinion on rails but I could care less about what music he's listening to now or what country he's traveling to now.

This is the exact problem that an algorithmic timeline is intended to solve.

Maybe not every tweet is as important as all the others. Maybe I want to follow a lot of interesting people, but not necessarily see every tweet about how much they like the hotel breakfast, or whether the conference provided a good enough AV system, or how good the broadband is in various SF neighborhoods.

Doesn't even sound like the GP is even following anyone. I've known a few people for whom the twitter interface and, well, really, the whole platform, just doesn't make much sense. It never clicks with them. None of these people had the "whoah... you're following way too many people!" problem. Almost the opposite, in most cases.

Yeah, you really have to cull it. If someone in your timeline isn't posting things you enjoy reading, remove them. I use it primarily as a media consumption device; I follow people who create and say things I enjoy. I only follow one or two personal friends. The idea of using it for any serious communication is ludicrous.