"Less control over your vape" would be more accurate.
The mech stuff follows battery voltage, and that varies constantly from Top-off charge to recharge-point as the battery drains. The main reason all e-cigs before mechs were regulated by some means is to give consistency. Even the cig-a-likes.
A lot of the same effect as sub-ohm can be achieved using a regulated mod and micro-coils, for example, with consistency (My Opinion). Also, a mod could be build to deliver a consistent regulated voltage even in the high amp ranges. It just isn't necessary to do so and is wasteful so they don't build them much. Although I have seen modders building parallel battery circuit stuff, so who knows. Would be bulky.
IMHO, the mech stuff is mostly a technophobe thing...."I can repair it if the apocalypse hits" kinda thing. Who would want a completely unregulated ecig otherwise? Sub-ohm vaping is a fad that saved, or made, the mech mod market. Without it, there'd only be a few (mechs predate the SLR fad as far as I know). We used to make simple mechs from scrap stuff in the early days. I have to say that the mechs have gotten pretty sophisticated with adjustable air flow and locking buttons and such. Nice stuff. But still, not regulated.