It's fun content, sure, but if you run it for 3 hours a night for a month will it still be fun? Remember this is the big content of the patch and it's gonna need to last until Shadowlands while still being entertaining. If people could endlessly grind runs it would be really boring after a few weeks. I do think two attempts a week is a bit low, maybe one per day would have been good, but then people would just complain that they have to log in every day or they fall behind so who knows.
I've done it on 5 characters so far, and been enjoying it on all of them, but I'm also kind of glad I'm not required to grind it for hours on each alt practicing the best routes for different specs and such.