No one in their right mind is going to use BTC as a currency as long as they expect the value to keep rising.
You know your cash will be worth less this time next year, thats the incentive to spend it.
In the 19th century, during the golden standard, there was a constant deflation. So what? Why spend gold and silver, if you can buy more for them next year? Because you need to eat today!
Even now we have a deflation with a lot of things. Why buy a new smartphone now, if in 3 months it's gonna be much cheaper, and in 1 year it will fall to half its price?
If bitcoin users have all their cash in BTC they will have to spend it some time.
All those deflation theories would mean that the Businessmodel of a credit card would never take off.
Because consumers are so wise with their spendings. WRONG consumers are fkin morons that spent their money as long as they have it and take credit if someone can give it to them.
Same goes for electronics, lets take smartphones, with the deflation theory Apples Iphone success would be never possible. because everyone knows that one year later apple will bring a phone twice as good for the same price, thats a HUGE deflation, not some 1-2% and still nobody give a fuck. Consumers camping days in front of the store to get one.
Deflation theory in my opinion an over exaggerated myth, to make sure the tax payer keeps using fiat money and doesn't question status quo.