Badly aligned expectations are perhaps worse than badly aligned interests because they spoil what could be an otherwise good relationship.

Shares that signify that the owners want a person to help run the company are different than shares as a form of payment. There's nothing wrong with either so long as everyone understands which it is. If it's compensation, then it's mostly a distraction from evaluating the job offer. The ringside seat to a rocket-ship ride comes with or without shares.