I don't think a reboot was going to go down well with fans (at least not all of them) no matter what for much of the reasons you listed. But if a reboot is happening and you want to keep the new canon fresher with a shorter timeline, you logically can't put multiple generations of heroes into it because there isn't enough time for more than the first generation to be barely established.
I'm not saying that rebooting/reduction were the only possible solution, or the most desirable one. But go all out, because trying to keep too many things in an alleged clean slate/new universe defeats the purpose and just creates problems. Just look at what happened in 1986.