If you're heading to grad school, it can be essential to have connections made through UG research. That's a trade that isn't just advised in some fields, but necessary. A letter of recommendation that says you're actually useful as an RA is 1000x more of a direct implication that they would benefit from bringing you on than an A in a few classes. Academics don't like finding out that smart people are impossible to work with any more than industry does, and since they're tied to you for longer, in some ways it's an even bigger deal.

You'll have a hard time getting an internship if you don't meet an arbitrary GPA cutoff.