There are so many things wrong with the new universe, that I can't even begin to list the number of better ways they could have simplified continuity without having to wipe out lots of great things in DC comics at the same time. This is the problem with DC reboots, they throw the baby out with the bathwater.
To be fair, the other reboots have never been as much of a clean break as this one. Some tried to unify worlds and sort out problematic contradictory origin stories (see: Donna Troi and Power Girl). However, they never just completely flushed the existing continuity, just altered it.
This new reboot is just horrible in that it wipes away most everything from the past. I'm hoping eventually they do some sort of return to the traditional universe ala Heroes Reborn, but I may just end up being disappointed on that front.
I'm still also pissed in the WAY that it was done. This whole time travel thing is lazy and makes no sense seeing as there are entire groups of entities in the DC universe that are supposed to stop things like this, such as Rip Hunter and the Linear Men. There's no way they would have let this happen. Also, altering timelines is par for the course in the established universe and it's never had this huge of a consequence. That mostly lies on the horrible shoulders of what a lazy, slapped together affair that flashpoint was.
Addendum: Also, as I've said before, it speaks volumes to how bad the circumstances around the reboot are when I'm more willing to accept:
1) Superboy Prime punching on the walls of reality so hard that it alters them
2) A giant, evolved Mr. Mind becoming an interdimentional moth that eats reality who is stopped by a hail mary pass from a repurposed Skeets.
3) Hal Jordan as Parallax destroying the universe and restarting it with a new big bang
All that unbelievably over the top stuff is more believable than Flash going back and stopping his mommy from getting killed.
