Why did they have to make it a reboot?

I didn't tend to think of it as a reboot either, but I thought it was playing with the idea that James Bond was an alias for whomever was designated 007.
Judi Dench's M it's probably the biggest obstacle to thinking of it as a reboot. There seems to be continuity from her Brosnan films.
And the rest of the Craig movies work very hard to undo any doubt that his name is in fact Bond.
But how the first 15 or so movies could take place between Quantum and Skyfall- was there a second cold war? With no cell phones?
I guess reboot is the only thing that begins to make sense.
But it's not a problem for me. I gave up on Bond movies after License to Kill, and then again after Tomorrow Never Dies... Quantum was maybe an interesting bridge to an end of a Quantos trilogy- but instead we got Skyfall- which made me give up on Bond once again. And probably not for the last time.