It's not "intellectually dishonest" to consider compromises 'compromises'. Either you gave up on your principles, however briefly, or you didn't. You just want to portray Bernie as a totally uncompromising candidate, when in fact he isn't.
After all, the greatest proof lies in the crime bill of 1994 that Inuhanyou likes toting about.
It's not wrong to be pragmatic. Reality simply works that way. It's also not better to be principled in every situation; see the Republicans. Sometimes the hardest and most difficult choices come from having to compromise yourself to fulfill something that you believe can do good; see Daniel Webster.
The difference with being pragmatic based on polls before every decision you make and actually having a stance that is unwavering despite public opinion is pretty big.