As can be seen, the padding is several inches thick and I can confirm it's got some cushion. It definitely isn't anything that I'd consider "hard."
(Hopefully obvious) Satire aside, we've been hearing a lot of complaints about the outfield wall and its role in hurting Carlos Beltran. This just in: Human bodies aren't made to run into a stationary wall at a high speed. We just aren't made that way. Even the freakishly athletic bodies like those possessed by Bryce Harper, Matt Kemp, Yasiel Puig and Carlos Beltran.
So, please, stop blaming the wall and/or the stadium.