No disrespect taken.
Let me ask you. How do you assess the value of 100 USD? Do you only consider it's value in BTC? Of course not. Then why would you expect that BTC could only be valued in USD? Buying USD is only one activity you can perform with BTC. BTC could also be valued in cars - especially if you are in need of a car...

I leave it up to the buyer to make the decision if the value of the car is worth 100 BTC. If to them, it is, then we have have an agreement. If they think it is not worth 100 BTC, then we can negotiate or not have an agreement. The same thing happens every day in USD transactions. This is no different. You can choose to buy US$3000 (or $2830 at the moment. Maybe $1800 or $5000 tomorrow) with your 100 BTC or you can buy my car.  The car is for sale for 100 BTC.