This reddit thread pretty much sums it up
https://www.reddit.com/r/Guildwars2/comments/3qe4rl/fractal_bosses_too_much_of_an_hpsponge_now/
Adding HP and lowering dmg isn’t challenging, Anet stop trying to justify stretching out the content here
1 Fractal now (40%) takes about as much time as doing half of the 4/4 fractals pre-hot which I’m sure was the intended purpose so that you think your going quicker but really your going 50% slower this is all still in zerker gear