I'm as pro PoW and anti PoS as anyone, but your case is not strengthened by the sloppy reasoning at the end:
In proof of work, when you setup your ASICs and start mining you're, intentionally or not, subsidizing decentralization as the rest of the miners suddenly have less power.
The same thing happens in proof of stake: To acquire voting power you buy stake from existing stake-holders, who end up having less stake.
The opposite happens in proof of stake: To acquire voting power you increase their gains.
Gains has nothing to do with it. If you buy ASICs from another miner, then you also increase their gains.