Yeah I wouldn't want that either. As a user I 'd rather have responsiveness over the realism of not being able to see the entire field. If they were going to do this I'd rather see them bring back the vision cone because I shouldn't be able to see all my receivers at once either. But I don't wanna start an argument over the QB vision cone though.
But I think the lack of a blindside factor for REs isn't really as much a problem in HUM/HUM games as it is in HUM/CPU anyway. The fact that the CPU has no concept of blindside is frustrating because combined with the fact that the CPU feels pressure from the RE as easily as the LE and automatically drifts to the QB's right it makes things that much more difficult for the RE to get sacks.
As someone already posted I think if they decreased the QBs vision raidus on his blindside AND stopped the automatic drift right then this could really help with the problem. I can't begin to judge how easy or difficult this would be to program. Though, it would be cool to hear whether this is something that has been/will be considered or whatever.