The only reboots that really bother me in principle are the ones that are too soon or unneeded.
For example Robocop was fine as it was and doesn't need a reboot. BSG had lain fallow for 30 years and the premise was rather wasted on the original show so a reboot was perfectly acceptable IMO. Star Trek...I think it desperately needed a fresh start, but not necessarily the one it got.
As for X-Men...the movies to date have been a little on the inconsistent side and somewhat incoherent to say the least so starting again with the First Class cast isn't at all a bad idea. I just feel sorry for whomever they get to play Wolverine once Jackman is done because that's not an easy act to follow.