> I count six times you used the word "currency". Yes, some people thought it would be that, but it isn't. It's Bitcoin.
Presumably "some people" includes its creators, given that "coin" is in the name. If that isn't meant to evoke currency, that's quite an oversight.
> It is not limited to 21M "units", and it never was. It's arbitrarily divisible into whatever units you like.
This response doesn't seem to address the parent's related point: that bitcoin as implemented seems to have inflation and deflation built in.
> Again, since it is not a national currency, it doesn't matter. It isn't "deflation" when the price of gold goes up.
It's certainly the giant problem it would be if it were a national currency, but that doesn't mean it doesn't matter. Speculation in anything can have consequences that are undesirable, and for that reason, it's often regulated.