A currency that dramatically changes is ability to buy real goods over time, isn't a currency.
It is just a speculative investment, which in short term can realize some profit, or a big loss.
A currency shouldn't necessarily have a super static value, and a small inflation (around 4-8% a year) is probably good, while deflation is almost universally recognized as a big problem. But for sure the value of a currency should be constant over time.
Accepting Bitcoin as a payment instead of a fiat currency, is basically a bet, that can appear very profitable while Bitcoin continues growing.
But Bitcoin isn't necessarily going to grow forever.
The value of every currency is generated by the fact that people trust this currency. No currency has an intrinsic value nowadays.
But, why should I accept Bitcoin as a payment, if Bitcoin doesn't warranty any stability in short and medium term (no one should ask to a currency a long term stability, because every currency has a certain risk of ruin) ?
For this reason the future of Bitcoin is uncertain. Bitcoin is working as a Ponzi Scheme: it has value because people buy Bitcoin hoping to resell them at higher value.
Most of the billions of dollars of Bitcoin exchanges that go on every day have no link with real life or real economy.
They are just the a speculations, that may last for some month, some year, or also forever: but Bitcoin isn't going to change the real economy on the world, because it is not a real free currency, the main goal of a currency being encouraging commerce and production, not abstract speculation.
Bitcoin is being used as a commodity that gets traded, and not as a currency.
As this commodity is not linked with a real value, Bitcoin is a Ponzi Scheme.
If it was a currency, than not having real value would be correct: because a currency is a instrument to measure value, and not a reserve of value. But being, as a matter of fact, a commodity with no value, Bitcoin is just a Ponzi.
And what about steem ?
Steem is different!
Steem is both a currency and a commodity, and as a commodity has real value: having more steem power means having more influence on the Steemit community, and especially gives the chance to promote posts, and this gives Steem a real marketing value that will increase exponentially as the community grows.
For this reason, also if I have no Bitcoins, I am very happy to have a bunch of Steem Power.
And that's why, of course, any reward of this post will be Power Up!