Yes of course I spend my Bitcoin. I like the idea of this wonderful currency a lot and I want to spread it even further! I think it is very important to do this! It is true that most companies may sell the BTC directly via BitPay or some other payment processor, yet, there are most likely big whales who buy those BTC instantly, because they're supposed to have contracts with those payment processors, as far as I know. So there's not much pressure on the markets (maybe only a slightly more limited demand)
Actually, I think the bitpay model of instantly converting to fiat is good for bitcoin. It adds liquidity to the market.
I might also argue that this is exactly what bitcoin is intended for... to be used as a means of transferring wealth. NOT as a store of value. It should not matter if bitcoin is $10 or $10,000. It's usefulness and desirability don't rely on its fiat value, but rather on the features that differentiate it from other forms of currency.
Though you state some good points, I would have to disagree on it NOT being a long term store of value.