General audiences go to see movies all the time with characters they don't know. I think the only reason to not create a new crew, is to gain support of the base. But I don't think the base would care either way. They'll either like it or not. Just like they like or don't like having Kirk and crew.
Not to sound curt, but I'm part of the fan base, and I would've cared. A lot. Without Kirk and Spock, there would be no "Star Trek" fifty years later. No disrepect meant to any other flavor of Trek (many of which I like) but Kirk and Spock are
"Star Trek", and if you're going to completely start over, why start anywhere else?