You have two airlines. One pull Service due to what it perceives to be unacceptable risk. Another airline continues to operate into the field operating a craft with similar approach speeds to the Q400.
It says a lot about the safety culture of flyBE. Wether or not someone else has operated or continues to do so is irrelevant. If flyBE feel that it's not up to their standard, has decreased in standard or has proved to be more of an operational and flight safety risk then they owe nobody any explanation.
The fact that there's little in the way of protest Fromm Dundee airport would perhaps suggest that there's something in it. Maybe they've crunched the numbers and it just won't be viable for them to upgrade service.