About 6 years ago I was negotiating with a VC for Series A funding, and we agreed to give up X for the funding. We get to the signing, and the terms were different and in favor of the VC. Asked for an explanation, he said: "My reality has changed."
Moral of the story: don't put matters into the hands of someone else's moral compass.
Commits on both sides put matters into the hands of the other party's moral compass. It's at risk of failure. And NLIs are meaningless. Pick a company that had an NLI in hand where the other party at some point said GFY. The road's littered with those carcasses.
The answer is a Contract. I'd love to see the collegiate landscape change so that the phrase "He/she's committed to X university" to "He/she's contracted with X university."
Only that will eliminate the b u l l s h i t.