Hi, I wrote the article. Thanks for the thoughts, but I've never added people I don't know or apps I don't use. Spam apps I was referring to are from other people that show up in my stream or wall, those "Billy answered a question about you" posts.
Back when Facebook was new . . . the friends that you had were people that you actually wanted to keep in touch with.
That's still the case with me -- I only make friends with people I want to keep in touch with. The friends you have may have changed in character . . . but I find that hard to parse as Facebook's fault.
It seems to me that regular prunings and a less promiscuous friending policy would solve your problem.