If they had done a straight reboot, then a lot of people would have complained that they were disrespecting 50 years of canon, including 5 TV shows and 10 movies, by essentially saying that it didn't count anymore. That absolutely would have happened, and that's why they went the route that they did. It truly is a "damned if you do, damned if you don't" scenario.
Yeah, the way they did it was actually the best and most clever choice they could have made-it doesn't disrupt continuity, but it frees them to tell whatever stories they want