It's an open question whether such substitutes will trade on par with the real "in-blockchain" thing. Personally, I doubt it.
If enough goods and service providers followed suit, current speculators would have to take a hilarious loss to buy anything.
what are you, the owner of 100btc going to do:
a) buy $100usd worth of goods at ebay directly
b) cash out at a proper exchange for $100,000usd, then buy $100usb worth of goods on ebay and have $99,900usd left over? or cash out ONE btc for $1000usd, buy $100usd of goods and have $900 usd left over AND 99btc?
How do you expect any even remotely rational players do participate in this farce?
Given the fact that current BTC to USD exchange volume is fairly small, it wouldn't take that many large global goods and service providers pegging their BTC/USD exchange rate to cause the speculation market to collapse.
Those that recently bought their Bitcoins at $900 would sell below the current high price to realize their gain and avoid a potential loss, then those who bought at $800 would follow suit, and so on.
In very short order, Bitcoins could be trading in single digits.
you are proposing taking for example a $100usb product and selling it for 100btc... which at current market value is the equivalent of over pricing it to $100,000usd. Who would buy that when they could pay $100usd for it instead or convert 1btc and functionally pay 0.1btc for it instead of 100btc. What global goods providers would mark up their wares 1000x and who in their right mind would spend anything on that.
Sure, if BTC was worth > $1usd and you were selling them at 1:1 everyone would leap to do that because now they are GAINING by spending their BTC with you.
But your proposal means they loose 1000%. I don't understand what motivates this switch over.
Issuing more buy orders cannot cause a drop in price.
In your scenario, you propose that large businesses around the world issue a practically limitless number of buy orders on BTC, supposedly at a low-balled price, supposedly inducing people to fulfill those orders...
You can't affect the price of anything buy flooding the market with an enormous number of low-balling buy orders. You can create a floor, but that puts a lower bound on how far bitcoins can call - it doesn't induce the fall.
What they ultimately want is to guarantee they're going to receive the equivalent of $X for every widget they sell, so they'll either have to declare that Y BTC = X USD regardless of market prices, or they'll have to accept whatever Y in BTC is equivalent to X USD on a given exchange on a given day -- which is essentially equivalent to doing business in USD directly, with BTC as just a weird payment mechanism.
Businesses are going to be hesitant to accept BTC for the same reason they don't tend to accept payment in kind -- you need dollars to pay taxes and wages.
And you apparently forgot that the total number of bitcoins is severely limited (around 20 million).
Both cases lead to significant losses for whoever is trying to peg BTC to some arbitrary constant value.
What are you, Satoshi Nakamoto?