The ratings are too poor for them to try it on MTV:
2007 - 921,000
2008 - 680,000
2009 - 647,000
2010 - 627,000
I couldn't find any 2011 or 2012 numbers, but given this year's show was primarily online only (with a 12AM one hour edit on Spike) on a much cheaper budget I'm going to assume ratings continued to slide. For comparison, the viewership figures for the 2013 MTV Movie Awards were 3.8 million viewers.