I don't have a dog, but I do read the Doghouse regularly, because I care about animals and all I've ever seen from DBF is someone who passionately cares about dogs and would do anything to help someone who genuinely wants to help their animals. I've also seen her on AIBU offering support and advice.
I agree, she's forthright and sometimes tells people hard truths that they don't want to hear, but I've also seen her get an absolute pasting for her personal life (not anything to do with dogs) and she's taken it in her stride.
Having been a moderator elsewhere, I know there's always a big back story to a ban, as when it's someone "popular" it can cause a backlash like this one, so the decision isn't taken lightly. But, I think DBF is the wrong target here.
I think she does make parents lives easier (if they have problems with their pets) and I also think that someone with her level of specialism is an asset to a forum like this.
I know I've recommended MN to friends who need advice about dogs and that's because I know (knew) that DBF would offer a sensible dose of advice and support if needed.
WRT to the thread being discussed, I read it and have followed other similar debacles involving the OP and agree with everyone else here - DBF was not out line, just at the end of her tether with someone she's repeatedly tried to help.
just my twopenneth, couldn't not stick up for DBF - I really value her contributions.