They claimed at the time that it was overuse, since KC started the season with a long road trip, then a long home stand with other events on the field during that time.
Bruce Arena was livid when LA played there, but only because I think he thought at the time the pitch had more to do with the tie result than KC being a legit playoff quality team.
Now that the field has a chance to grow through the sand base and rest for a few months, I would think the pitch will be the world class field it was designed to be. Believe it or not, several top flight teams, including Barca, came to KC to copy some of the innovations at LSS Park, including the turf and drainage system.
Bottom line: KC weather stinks for quality turf. Super hot in the summer. Super cold in the winter.