I disagree. Kendall did a wise choice and went straight to high fashion world. Didn't do pin-up, playboy-like things like Emily did. Worst mistake Em did was that dumb Blurred Lines video. It cemented her spot of a nude model instead of a fashion model. She's also reportedly short, so Kendall has an advantage there. Plus Kendall has the connections.
Also who is to say that Em was actually getting a lot of offers, or at the very least well paying offers? I doubt that if someone like Dior would come with millions of $ she would say no.
What I like about Em tho is that she seems like a good girl (yeah she has her rants, but who doesn't) and she seems to be dating the same guy for years. I always find that positive. She's not "climbing the fame ladder" through famous relationships (like Hadid girls do).