Back to the original question, why does everyone hate the idea of a reboot?
1. Because we have no reason to expect it to be any good.
2. Because it will interfere with the lore and besmirch the established series that we love.
3. Because reboots have a record of limited artistic merit - some are good, most are bad.
4. If the comics are any indication, follow-on stories to the original series will have to be better than the mess we got in Season 7 when it was obvious they ran out of ideas.
5. Diversity is fine and there may be additional stories to tell as a result but this smacks of just getting points from the world of identity politics.
6. No one seems to be willing to make this actually happen - they have selected a writer but she has not written anything yet.
7. No one on the program buying end who would actually televise it seems to be pushing actively to get a pilot made.
8. Joss will be wrapped around the axle with "The Nevers" and will not be able to devote time to Buffy 2.0.