The argument for not signing is based on readiness. If you are marginal for making the big squad, you should stay in college. The money will be there next year. Oshie certainly could've left after 2 years, was a first rounder, but he would've wound up playing a year in the AHL...almost certainly. He got the same money the next year and didn't spend a minute on the bus.
Nelson spent his whole first year pro in the AHL.
Remember what a $270k signing bonus turns into after your agent, accountant, and tax bill...your putting $140k or so in your bank account. Time value of that for a year assuming 5% net return is $7000.
Now, if your family is in serious need or something I totally get taking the money, but if your family is fine and you are on a full-ride at UND...what's $7k worth???
If you're playing in the W and have given up your amateur, then you sign the minute the offer is there.