If they did that, people would come back. Hey you've made it to rank 51 solo in 87 hours Mr. Gnome shifter. Umi said no way you could do it in under 100 hours on a def/def shifter without porc. You get two quests forms of your choice, three legacies, seven edges and the aura and barrier spells on tap. Now go see if you can PK that Storm paladin with six virtues, emperor powers and DB who is dual wielding defiance and bal talon. Just ask the 5 path 3 adaptation orc shaman to come help you out.

Then he posts the log and everyone comes back, the Imms are forced to stop doing it, and everyone leaves

Then there is nothing but Imms, which is when they'll finally open everything up, run around vis and do all the fun shit in CF, taking down ancients and all that good stuff.
They just don't want mortal eyes seeing them in their playground. If I was an Imm, I'd honestly run around when there were not a lot of mortals about just annihilating everything for fun. What's a few hundred dead NPCs for my amusement? Hell, even if mortals were around, who cares. I'm an Imm.

I would actually play CF if I knew I was the only one ever logged in.
Would be a fun RPG for a bit, though a lot of the insane stuff I could never do solo unfortunately, even with a perfect build and gear.