Girls and Boys !
Your calculations does not take into account that thing that UNTIL the whole markets are banned you are earning 10x in every month with ASICS so it really does not matter do you get 50% back (or even a bit more) from your initial investment when the game ends.
ASIC miner just throws the worthless ASICs to a trashbin and walk away 9x richer than GPUs owners...
Well that's not assuming worst case scenario. Its assuming the market will hold up for at least X months. ASCI probably pull ahead if the mining conditions remain steady for 8 months. If that's guaranteed, I'll go with ASCI too, but it's not.
I assume worst case scenarios for risk management, which is everything crashing tomorrow. To me $10K of ASCI is as risky as $30K of GPU rigs. And $30k of GPU rigs make more than $10K of ASCI, hence the main reason I choose GPUs. I'm also limited by my risk profile, not capital which is another factor. Just my opinion.
There's definitely valid arguments for choosing ASCI and diversifying between ASCI and GPU.