My theory is they are trying to gobble up a bunch of blockspace "real estate" by putting their little inscriptions on specific Satoshis with the idea that they will be worth more someday.
They think it's an investment that will pay off eventually when hyperbitcoinization happens, that they will be equivalent to rare pieces of original artwork. The earlier the block it first appeared on, the more rare and valuable it will be. Someone with deep pockets has come to this conclusion it seems.
There will be 2.1E15 satoshis on the chain, so the amount of these inscriptions that could be made is very high. Most likely what's going to happen is they will overinvest and create such a supply glut of these things that they will be worthless. Then this whole episode will be forgotten by everyone except a small niche is people who won't be able to let it go and move on.
Idk though I'm just spitballing.