I think that I can claim a sense of humor. I can’t imagine that those who know me would not acknowledge that I can be wry, sarcastic, outrageous, droll, slapstick, sometimes vulgar and perhaps even an above-average punster. But that doesn’t mean that I will find humor in everything you think is hilarious.
So, if I criticize a meme or take exception to a “joke” please do not respond by telling me it is just a joke or telling me that I need to get a sense of humor. And I will promise to continue not telling you those things if you criticize a “joke” of mine.
“It’s just a joke” is not an excuse for being offensive. “Lighten up” is not a defense of inappropriateness, pointlessness, or trolling. “Get a sense of humor” does not address actual issues raised by objections to humor or attempted humor or the harm they can cause.
Humor is one of the most telling aspects of the norms of a culture. We are either laughing at those things which are not “normal,” or we are laughing at those things which are so normal as to be indicators of our common foibles or faults. And it is usually possible to tell the difference. When we laugh at the “other” we are doing something very different from when we laugh at ourselves.
I have recently been seeing a new emergence of “humor” based on prejudice, bias, and the kinds of racism, misogyny, homophobia, xenophobia and downright meanness that we seriously need to marginalize, not re-normalize.
So, a few suggestions from the point of view of my sense of humor.

1. Any joke which is not funny unless you make the butt of the joke a “dumb blonde” (or any other hurtful stereotype) isn’t funny to begin with. Any joke that is funny already is made less funny by making the butt of the joke a “dumb blonde.”
2. Any joke that uses an outrageous caricature of a Mexican or an Arab or an Asian or a person of color any other race or nationality in order to mock their culture, their customs, or their pronunciation of words in a language which is not their first, is not funny.
3. Any joke that marginalizes or grossly distorts the reality of any culture, nationality, race or group of any kind is not funny.
4. Any joke based on belief in a conspiracy theory, a deliberate untruth, or a misleading and debunked claim is not funny.
5. Any joke based on shaming of any kind is not funny. Any joke that targets the fundamental humanity of any individual or group, that furthers destructive stereotypes or keeps us from seeing each other as equally deserving human beings is not funny.

What is funny?

1. Jokes that point out the human frailties we all share are funny.
2. Jokes told by those on the inside of a group about themselves are funny when they tell them (but not when outsiders do).
3. Jokes that speak truth to power are funny.
4. Jokes that play with our common language, both verbal and non-verbal, are funny.
5. Jokes that point out the absurdities of life or create their own absurd universe are funny.

There are, of course, occasional exceptions to these “rules.” But those can be accounted for by differences in where individuals see humor. I don’t really mind if you don’t find something as funny as I do. And long as you focus on what is or is not funny about it, I won’t mind if you tell me it isn’t funny. I might even, on reflection, find that I understand or even agree with your perspective. I have no problem apologizing for “humor” of my I own if it has hurt someone, however unintentionally.
The problem I see here is that humor is becoming a dodge, a way to be mean-spirited, bigoted, and even cruel without taking responsibility for it. “It was just a joke” is simply another way to say, “I didn’t mean it.” But that’s a cop-out. It’s a deflection, a way of making the other person the problem rather than the action itself. This is what bullies do, and “humor” is becoming a way of bullying.
I love a good joke. Humor is an art form, and like all art forms it exists along a scale from simple, vulgar humor to sophisticated, complex humor. And at every stop along that line we can all find something to relate to. And like all art forms it has its genres, its specialties, its in-jokes, and its avant-garde, so that not all of it is equally appreciated even by its greatest artists or most astute critics. But I value genuine humor enough to call it out when it becomes hurtful, when it reinforces the stereotypes and biases our culture would rather keep in place.