Blizzard
was bringing the skill requirement more in line with what it has been in previous seasons. The vicious mounts are meant as a participation reward for players who are trying, even if they aren't necessarily highly skilled (with the Gladiator mounts being the skill-based reward). The rating requirement only exists to negate "tank your rating as far as possible so you can win a bunch of games in a hurry" as a cheesy way to get it (which would in turn have pretty disastrous effects on the overall ladder)
