I'm also in favor of the old separate lists system. It was one of those changes that happened without anyone wanted, demanded or complained about, still it happened. Reason for it was psychological: so people don't feel separated from one another in a way, if i remember correctly. Nevermind that we are separated by servers, that's cool
Hate to base this post solely on my memory because that potentially arises problems, though i'm confident that was more or less the main reason.
Even tho i suspect your reason for this thread is slightly different then what you're actually complaining about I'm going to go forward with my two ideas to bring old system back:
First is because it makes browsing server list much more practical, faster and intuitive. Confining lists to Demo/Licensed instead Demo/S1/S2 only would be a slight improvement in my opinion for the same reasons.
Second is psychological (yeah, i'm doing it). Getting to the licensed list feels like an achievement no matter how u look at it (or how mature you are). That feeling there is more than meets the eye. Popel would want to get on that list, aka ching-ching for further development (cba subtlety atm).
No to mention lack of server/buddy favorites, which would greatly contribute to any kind of server list. And so on and so forth...