The initial questions page after login should be the ones showing those questions on your added/favorite tags. Since they are your favorites, it sort of works as the tags you follow.
Every time I go to any Stack Exchange site, I would always need to go to tags again and again.
This feature would sort of work like Facebook's news feed/timeline, but instead you get the latest questions from the tags you are following. I know the questions tab needs to be retained as is but couldn't we have another tab that would display the ones I mentioned above as the default?
Anyway, in my own experience, since I don't know much about other languages like Ruby or Python (I'm more of a PHP guy), then seeing Ruby or Python questions doesn't seem useful in the default page. Instead having a default page of PHP and all other tags I added would seem more helpful. If users insist to look for other questions, there is the old question tab or the old tags tab which users can navigate to.