From what I've seen around the game community in general, I think there are as many people who would START playing INF as those who would leave should it officially move in the direction RA takes it.
I've been playing INF since version 1.5 or 1.75 (well, whenever the M16 was still an A1 and fired on full auto

back with Unreal 1, and over the last couple of years have seen INF evolve into a really spectacular and ambitious piece of work that has become my favorite action game, bar none. Maybe its because I've seen where it has come from that I am much more forgiving of the quirks that come about, but for whatever reason I have stuck with it, defended it, offered my criticism and devotion as it moves closer and closer to what I remember it being about when it was an infant.
IMO, from the trend that started back with Unreal 1 between Serpentine, Navy SEALs and Infiltration, RA has only helped continue to polish the model that Infiltration created, and I have practically come to see it as an interim update to the game. I've said before, I personally find RA sniping much more rewarding. I find it much more intense and enjoyable, and i get to share the experience with players like those that actually went to seek out a 'realism' Mod for Unreal 1 before the masses had really been exposed to them.
RA is certainly geared toward a certain demographic. Some people have been scared away from Infiltration through its changes, others are drawn to it and this will continue to happen. I feel confident there will always be a following no matter where Infiltration goes, I for one hope it stays in the direction RA takes it, but I will keep playing regardless. I have yet to be so put off by the team that I would make such a brash statement as to 'never play it again!'
Anyway... For those that hate the scope sensitivity, have you ever fired a scoped weapon? A scope does not make aiming easier, it is only a device that magnifies light, not the target itself. If you can see something without a scope and can't hit it with iron sights, a scope would only let you see what you are missing better

Now bipods/tripods on other hand... And as far as complaining about the sprinting speed, please go stick on a 100lb backpack and heavy hiking boots and run through the dirt as fast as you can. Time yourself, see how you feel.
The point is simply that for many of us, to ignore these especially severely hampers the enjoyability of the game because at the very VERY least, we do not want to be supermen. These are very basic factors that, when ignored in a game, have the effect of immediately shattering any illusion that what we are experiencing is in any way real*istic*. At least thats the angle I take on it.
When I sharpshoot, I want to feel that I accomplished something because of my superiour marksmanship, not because I was handicapped.
And personally I think that being able to sprint constantly and not have to take time to aim is FAR more a handicap than RA is.
Frankly, I don't even see how the opposite IS logically a handicap by the definition of the idea.