As an alternative argument, why in the world would I want jump that much in difficulty so quickly?
I'm not THAT quick on picking up the game.
I would rather not jump straight from AR 9 to AR 10 and OD 7/8 to OD 10. DT is a good middleman with AR 9.6 and slightly boosted OD.
Eventually I'll get around AR 10 and HR and it'll end up in a progression as linear as when I first started playing. I'll definitely try to further +1 or +2 this by then progressing to AR 10.3 (AR 9 + DT) and then finally AR 11 (HR + DT), but that is a LONG ways away.
It's as if people expect me to become Cookiezi overnight saying stuff like "I thought you were trying to get on Cookiezi's level, you're just another Sayo".
There's gonna eventually be a limit to DT AR 9.6 maps that I can play for pp (roughly 210 or 220 pp from a decent play) and when that time comes, yeah I'll try as much as possible to understand how to play with Hard Rock (and when that time comes, expect a considerable downtime of 0 pp gains). But that time is not now.