I'm not using my MBP to render 4k video or maxing all cores of the CPU for sustained periods.
It seems clear to me that for the casual/developer segment, that has eaten up the entire marketshare, having short bursts of peak performance on six cores is perfectly fine for compiling/coding/browsing workloads.
You'll have a hard time convincing me that sustained 100% cpu tasks should be run on portable hardware. Use remote desktop/SSH and a VM/Mac Pro if you need to hit maximum TDP for long periods, RDP has great in-house latency and has the added benefit of your lap not becoming lava.
There's a much better pattern for these tasks, and it isn't using hardware designed to be portable. Just because you can doesn't mean you should.