I skipped after page 1, but my personal defense for Flash still being on my bar is that for times when you need to buy an extra second or two to line up/gather adds for overpower to do the real work. The 360 degree aspect is what I use it for more than anything. Yes I know Steel Cyclone does the same, but I can hit flash once or twice as I'm moving to position, where Steel Cyclone I want to be 99% sure to hit everyone.

More applicable to speed runs, and when I do content that doesn't require that sort of gathering of mobs I do remove it, but even without being as strong as SC/Overpower and not something to rely on for hate, it still has it's uses.