Hmmm, well I'm generally anti-Reboot but I must say I kind of agree on B5 though I think "remake" would be a better path for them to follow really. While some people will cry heresy, B5 suffered from having some big ideas at play, that went beyond the writing abillity of JMS and the show suffered for it, in a way that goes beyond him simply being concerned about what plot lines could continue season to season due to the show's future being in constant doubt. Not to mention the fact that it had more problems than just some dodgy CGI which has aged paticularly badly today, especially to begin with, very few members of the cast could act, and some of them like Claudia Christian never seemed to quite get the knack for that acting thing even years into the series, of course I in part blame the writers for that as well as it seemed to me that they would continually step on characterization whenever it was conveinent despite the pretensions of an ongoing storyline. Now that we pretty much know the entire story of Babylon 5, what's supposed to happen, etc... planning out the entire script from episode 1 to re-tread the entire thing at a higher quality could work.... as far as rebooting it goes... I figure there is still no point because I feel that if your going to do away with enough to make a "reboot" you might as well just make an entirely new space opera TV series set on a space station from scratch without trying to attach a fairly well known name to it.
I'll also be kind of blunt in saying that making a more condensed version of "Harry Potter" would defeat the purpose as it's the depth, world building, and casual minutae that make it what it is, and cause it to stand out from other works of childrens fantasy. You remove all of that and "keep to the point" and it's not "Harry Potter" anymore, it just becomes another story about a magical kid with a destiny fighting some evil thing. It sounds silly, but the depth is why something this childish even has adults wanting to go to theme parts to immerse themselves in the world and it's details.
As far as "Gargoyles" goes, I heard a slightly differant tale of it's demise. Apparently it was conceived at a time when it was believed that there would be a niche for prime time cartoons aimed at an older audience, the same basic logic that spawned the beginnings of the "Batman" animated series which also failed. "Gargoyles" was late to a market that never materialized, got restructured a bit for "teens" and wound up having a pretty strong start, with strong writing, and a cast of then-known actors still flying fairly high on their TNG fame (Jonathan Frake & Marina Sirtis) doing voices. It's continuation was conceived for this new niche, and was nothing like the first episodes it ran with, which managed to butcher what fan base it had been putting together, namely because the original set up, as campy as it was (remember it was competing with things like Batman) was deemed a bit too dark. Incidently I'd have to do some checking but I seem to remember Gargoyles got some attention at the time for actually showing blood in a few of the episodes during fight scenes, not over the top gore, or anime-type "ulta-violence", but for example in one scene where Goliath gets nailed in the face there is some droplets of blood flying away after the blow which I seem to remember being a big deal at the time... and pretty much the kind of thing Disney didn't want to be associated with if it
wasn't fighting in a very specific arena.
As far as a reboot of Gargoyles goes? I don't really think so. It had some cool ideas, but I think it's better to just leave it where it was. That said, with the anime fad dying out it has occured to me that the market is primed for new attempts at more mature western animation on TV... a few successes like "Avatar" have helped cement the possibility, though truthfully I think it was trying a little too much to copy eastern conventions rather than being entirely it's own thing. Another show like Gargoyles wouldn't be amiss. I doubt we'll see that happen though, networks are stuck in their ways, and it seems like it's still pretty rare for there to be anything other than "kid toons" (maybe with some adult referances), or "adult swim" type fare. On the western front there also seems to be a tendency to be as stylized as possible as opposed to trying to create a sense of true internal realism, that detachment being the excuse they use (feeling they need to have one) when conveying their material.