“I would think with the state of the world today, that there are more important things to worry about than when one can listen to music.”
There are also more important things to worry about than whether or not we can eat pork, but it doesn’t mean that we should. You can “worry” about more than one thing at the same time.
“But it’s mitaam minhag, not mitaam halacha. My point is that people need to be educated.”
It wasn’t clear that that was your point. The whole concept of minhagei aveilus during sefira is technically a minhag, albeit minhag klal Yisroel. I’ve heard people unironically make the case that they are Baal Teshuvos, therefore they have no minhagei avos, therefore they don’t have to keep sefira minhagim at all. This is the risk of going around telling people it’s “just a minhag.” Most learned people already know, and many unlearned people would misunderstand the meaning.
“I just wonder why 33 days of mourning for 24000 and zero for 6 million”
You could say stuff like this about virtually everything we do. I’m personally happy not having a Holocaust-centric religion, but if you want to carve out another 33 days somewhere else in the year you can give it a shot and see if it catches on.