How does USD stop people from hoarding?
Do you honestly need an explanation why stashing USD under your mattress is financially not a good idea?
...if inflationary currency is needed, then so be it, you can petition to change Bitcoin to inflationary. You can go ahead and push for your ideal model. It has nothing to do with PoS, since it can do both.
Bitcoin is also deflationary, how do you stop people from hoarding Bitcoin? How does PoW vs PoS have anything to do with this?
I'm not pushing for anything. I see some pros and cons with both PoS and PoW, while you seem to stuck with logic "PoW sucks because of mining costs, therefore PoS must be perfect".
Lets take this scenario:
1) You have X PoW bitcoins, which is x% of total existing bitcoins. Since new coins are issued every day, if you want to maintain your x% you have to be active. You'd have to buy/mine/invest/scam/steal/gamble/create new BTC business/lend out etc.
2) You have X PoS bitcoins. To maintain your X% of total BTC, you have to do nothing, you just need to stake up all your coins in the wallet and don't use them.
Which system promotes activity and which one discourages it?