and what about youtube, yup google and facebook wasnt first, but others accepted them very much, but in crypto currencies no one want to accepted other then Bitcoin.
not true... almost all of the crypto's have some level of "acceptance"
There are lots of businesses and individuals that won't accept Bitcoin
at all... and quite a few that do but not at anywhere near spot prices...
they set their own exchange rate if you want them to accept Bitcoin
as payment for services (one that I know uses a fixed $30:1Btc value)
otherwise you need to cough up real US$
but acceptance alone doesn't prove or disprove legitimacy...
there are some government agencies that will not accept their
countries own currency to settle payment for transactions.