Not sure why you're digging so hard for excuses for SF4's life span. It's unlikely to get dropped because it's still popular, people still enter in droves, and stream viewers still tune in in droves.
It's that simple.
I'm not "digging" for anything. Dunno why you are "fishing" for something that isn't there (or singling my posts out from others saying the same thing). In the same quote, I also say its unlikely to be dropped.
Saying that its popularity has some to do with the time its been around and the revisions its had (which also seems simple) isn't anything other than using logic. You don't need to get defense force-ish. As people mentioned, MVC3 got hated on pretty hard in the beginning as well. Others have also mentioned that people didn't have the same claims of having figured everything out within 3 weeks of the titles release as many people seem to be doing with SFxT. It takes time for systems to settle and people to understand that same graphics does not mean same game. Relying on what is familiar and comfortable should be expected.
I'm glad you like SF4 though, more interest in any fighting game is a good thing for all of them in general. Hopefully they scrap shortcuts and comeback mechanics for 5. However it would be nice if people that liked SF4, would actually play other fighting games (even non-capcom ones) and give them a chance to succeed, but generally this is not the case from my experience.
If I had a choice between a safe, established game vs an unknown blow up or time out game when it comes to a tourney, I'm obviously going to go with what I have more experience with. Doesn't mean I like one more than the other in the slightest though.
Given how many new games there were this year (and others that are coming), its not unreasonable to have the oldest put to rest to allow the others to breathe. The season finale of SSF4:AE on WNF last week was the most unhype finale I've seen in a long time, no one cared at all. So I imagine I am not the only one waiting to see SF4 put to rest.