Re: Why are reboots (ST, Bond) anticipated, generally well-recieved ..
But Brand New Day wasn't so well-received?
Isn't the theory behind reboots that the former continuity was too complicated, boggled down, and a radical "return to the basics" was needed?
Isn't that somewhat the reasoning behind BND, that an unmarried (implicitly, younger acting) Parker made a better character, was more accessible?
There's no single theory behind reboots. After all, it's not as if James Bond had a complicated continuity bogging it down; they kept recasting the actors and never mentioning it, so continuity clearly wasn't a priority.
The problems with
Brand New Day were severalfold. One, not everyone agreed that returning Peter to an unmarried state was desirable. Personally, as someone who's not only read but written
Spider-Man fiction set during his marriage, I think it was a vital and worthwhile part of his story and shouldn't have been eliminated.
Two, the way it was done was awkward. They were trying to have it both ways, both change Peter's past yet keep it all the same so they didn't have to rewrite all of Marvel continuity, so they concocted this messy halfway thing where his past really did happen but nobody remembers it except for the parts they do remember, and it's all very sloppy and confusing. The problem is that it
wasn't a reboot in the sense you're talking about -- not a restart of the universe, just a reshuffling of elements of it within the context of a larger Marvel Universe that remained unchanged. And that was just a mess.
Three -- and this is the big one -- they had Peter effectively
make a deal with the Devil to save Aunt May. Marvel's flagship character, their greatest hero and champion of good, made a bargain with the embodiment of cosmic evil for personal reasons. Many people see that as an unforgivable act of character assassination. Worse, the professed reason for doing it this way was because the editor-in-chief thought it would make Spidey a bad role model if he got divorced.

What the
hell?! Divorce makes you a bad role model but dealing with Satan is okay? That's just
dumb.
I would add, though this is just my own view and not one I've heard widely expressed, that it was a terrible mistake to erase everyone's knowledge of Spidey's identity, including Aunt May's. Letting May in on Spidey's secret was the best thing that was done with that character in, well, just about ever. She made a marvelous confidante for Peter and was far more fun and interesting as someone who was uncomfortable with his life as Spider-Man but strove to support and encourage him than she ever was as the clueless old lady who had to be lied to all the time. And just in general, I think the whole "I can't let my loved ones know my secret" thing is limiting and cliched. The loved ones' stories are always more interesting when they're in the loop than when they're kept in the dark.
So not only was BND badly handled, but in many people's view, it wasn't necessary. It was a "fix" for something that only some people felt needed to be fixed, and it was done in a really, really bad way. Even the guy who
wrote the story, J. Michael Straczynski, has made it pretty clear that he didn't want to do it, that he didn't agree with what his editor wanted him to do.