Society and culture change. If I knew that something I did was perceived as being offensive by someone else, I would probably adapt for that person, because I'm not an asshole. This is true for something I just learned about an individual person, and it's true for entire segments of society where culture has slowly shifted over years.

Many conservatives have an affinity for the status quo, or the world as it was when they grew up, and they're going to resent being made to feel like they have to change. Some may be disconnected from modern or liberal culture and may be hit with a lot of new information and associated feelings about how offensive their speech or behavior was, all at once. They may be a little more skeptical, confused, and resistant as a result.

Others may be well-intentioned and may try to change, but those neurons are pretty stuck in their current configuration, and changing words or habits can be hard.

We should be forgiving and patient of people that try but aren't perfect. We should call out assholes as assholes. Everyone else, just assume good intentions, explain, and let it go.