Good discussion here. From my perspective it is a matter of tolerance. In the first instance of denial of service (LGBTQ+), it is due to prejudice, bigotry, ignorance and the like, which is just plain old intolerance of anything different, with disregard for reasonable analysis of the effect(s) of the thing or behavior objected to or to the recipients of the denial of service after the fact.
In the second instance, it is intolerance of intolerance, which is not only justifiable but necessary to maintain a modicum of civility within the society.(IMO)
While I would prefer not to have to resort to such tactics as denial of service, the usual alternative is to just ignore the background reality and behave as if everything is copacetic. This method lacks any opportunity for learning. While the group of bigots may not use the opportunity to learn how to be more tolerant or accepting of others’ differences, they will certainly be likely to learn that their unacceptable behavior cannot and will not be tolerated by reasonable people and that they cannot expect to get away with that behavior everywhere…and that’s a good thing.
Edit: GTFO