Why do you people think that ASICs are what cause centralization? This has to come from a place of complete ignorance.
NEWS FLASH: There are massive GPU farms out there, going to ASIC would just be a hardware swap, nothing would change.
I manage over 10,000 GPUs myself.
Why would anyone want to pay $5000 to build a 6 card GPU rig versus buying a $2500 ASIC?
Try using logic when posting instead of emotion.
They cause centralization because the companies making them also mine with them in secret before they release them to the public months later.
Even then, they only sell to the public to make room for their new generation of ASICs, that they will again sell to you you some months later after they have in private driven up the difficulty. Rinse and repeat.
At least with GPU's there is a level playing field, as your 10,000 GPUs are of the same generation and hashing capability as a home miner with 10 GPUs, so the only difference is scale not hardware supremacy.
Also, GPUs can be used to mine other coins and algorithms, where with ASICs once the next generation comes along the old versions become pretty much useless.
GPUs can still be used for gaming and other computing purposes, meaning that your $5000 mining rig example will be useful 12 months down the road, where your $2500 ASIC is basically a paperweight.