That's why someone bought this domain [0] which redirects to a search excluding tweets [1] not authored by the people you follow. It's way sparser for me (I follow roughly 200 people) than the regular twitter feed so I also waste way less time whether procrastinating or looking for tweets by people I actually follow. I deleted "twitter.com" from my browser history and always start at realtwitter.com now.

[0] http://realtwitter.com

[1] https://twitter.com/search?f=tweets&q=filter%3Afollows -filter%3Areplies&src=typd