I'm not talking about money, I'm talking about fame. They're desperate to be famous. From that shitty IFLD song that was a blatant attempt to get on the radio to Jack's "relationship" with Holly Madison. They try way too hard. Come on, do you really think MTV thought of All Time Low? My guess is that they contacted them and said they wanted to punk Demi. Demi happens to be an actual celebrity so MTV agreed. No one outside of this bubble cares enough about this band to want them on their show.
They've been on so many MTV shows; hell they have their own MTV unplugged... It's not like they're any sort of stranger to MTV.
And come on, there are very few guys who would pass up the chance to date a playboy playmate. Go ahead and ask around, thats not a "desperate attempt at fame." I Feel Like Dancing is a fun catchy song (what band in this scene would pass up the chance to work with Rivers, for real?), people put too much thought into it.
And really, why's it matter so much?