The anti-Cruz folks seem to be acting like "of course Ted Cruz won Iowa, it was tailor made for him". Well, no, it wasn't tailor made for him and he had to overcome a large number of challenges to win the state. Here's a list:
1. The media which seemed to give Trump 24/7 free coverage
2. The ethanol lobby that pretty much owns Iowa and hates Cruz for opposing ethanol subsidies and mandates.
3. A popular Governor actively politicking against him and for other candidates. It was also clear that the two sitting Senators were against him
4. A large number of candidates that were all vying for the voters most likely to go to Cruz. Carson, Huckabee, Santorum and Paul weren't an awesome bunch but they did garner over 16% of the vote in Iowa. Luckily Huckabee is already out and in a week, Santorum and Paul should follow soon after. Hopefully Carson calls it quits too since he simply has zero chance.
5. Establishment candidates not named Rubio not doing well. Although there are a large number of establishment candidates, they only totaled 8.4% of the vote. They didn't steal that much from Rubio.
When you look at all that, Cruz clearly wasn't a shoe-in and overcame quite a bit. Heck, New Hampshire doesn't seem so insurmountable after that now does it.