There are not many people specifically acquiring bitcoin just to pay for steam games with it, where it will be converted right back. Maybe some to test. Questioning the value as a result of the "usd -> btc -> usd" transfer isn't really applicable because it just generally doesn't apply anymore.
No, that's your only measure of success. In order for Bitcoin to succeed as a viable payment platform, businesses also need to adopt it wholly, which means actually conducting business in Bitcoin rather than converting it to a "real" currency as soon as possible.
Basically, if they are treating it as hot potato, that means they see it as too unstable and risky.
I don't understand the need to require a business to hold the bitcoin in order to consider bitcoin a "success". In this scenario bitcoin has succeeded as being a cheap method of transferring value.
Eh, I'm not so sure. You are probably right, but at the same time they probably want USD for the same reason they get USD from Paypal or their merchant bank when someone pays in a different currency.
Is Paypal not a viable payment platform?
There are two parts to Bitcoin - some folks think it's a great store of value. I do not. I think it's an amazing decentralized transaction system that can replace VISA/MC - not replace the US Treasury.