Because it doesn't claim that. Hologram != Simulation.
The FTA is throwing around the word hologram, but IMHO that is a bit a stretch. Or maybe I don't know the official scientific definition of a hologram.
It just means that our universe seems to have more dimensions than it really does, for certain purposes. By analogy with a visual hologram, which looks 3d but all the depth information resides entirely in the interference patterns encoded in a 2d image.
It doesn't have anything to do with a holodeck or the universe as a simulation or even really invalidate the laws of physics as we currently know them. At best, it might mean that someday (a long, long time away) we can find a way to cheat certain of those laws that exist only as emergent behavior from the actual underlying system.