Further, in the department, I think she is one of the people who cares most about teaching. She runs the undergraduate summer research program. She re-does her class on PGMs substantially almost every time she teaches it to try to make it better. (Though such a high rate of change may or may not be a good idea.) Daphne is almost certainly one of the key people behind the *-class effort at Stanford CS.
For those with a negative impression of Daphne, my guess is just that they are misinterpreting her directness. If she thinks you're wrong, or you're doing the wrong research, you'll know about it.
(Also, Ullman is one of the nicest people in the department in person, which is crazy given that he wrote the standard texts in compilers, databases, and arguably automata. He's emeritus these days though.)