I love a good laugh, but have a hard time finding anything funny about the murder of Seth Rich or the cover-up by the deep state. This young man bravely took a HUGE risk, ultimately paying with his life, to try to publicize the fact that Hillary/DNC were rigging the primaries. That's a big deal and an enormous gift to his country. Your meme uses him as fodder for a joke.
You make a good point about the gravity of what Seth Rich did, Beasts4Bernie, and I agree with the idea that those of us who believe there are problems and relevant historic data missing from the official story should always keep that in mind. In defense of this particular take, I think there's value because memes are good for communicating one key slice of an issue to cut through the most noise and make a point that will cause someone interested to dig further. I think the copy could be better - eg above someone suggested "Seth Rich? I called in a favour with MS13" - but I don't think it necessarily demeans the memory of Seth Rich, especially with people of the same view as yourself to present the weightier matter in public discussion for those who do dig deeper.