I think with 50 Shades it was a lot more than just trashy stuff. Watching reality TV for free from the comfort of your own home is a lot dfiferent than going out and spending money on three terrible books. 50 Shades is also a lot more successful globally than probably anything else of its type: all the shit that airs on E! and TLC doesn't actually rate that highly.
Keeping up with the Kardashians proves that theory wrong and don't forget the Georgie/Jersey Shores and all those red carpet stuff. People like random trashy shit for shits and giggles. It's fun, it's just mindless stuff. I come back from work and hell do I want to watch something heavy straight off the bat.
You guys are so overthinking it.