Well that is a weakness but considering the entropy deck does have 20 Entropy Pillars, you can usually be blocking around 30-40 damage per turn, so you should have a fair chance against a lot of decks.
You also forgot to note the large weakness to quanta denial or Dim Shields which are probably larger problems.
Anyways I'm just trying to post a unique semi-functional deck idea. I mean where else have you seen decks comprised of two thirds pillars with Fractal running off the mark?