1) Bitcoin is deflationary and it will cause it to fail.
2) Bitcoin is doomed to fail because people hoard it instead of spending it. No Economy exist.
3) Nobody uses Bitcoin for anything (Not Mainstream=Not real???)
1) How exactly being deflationary would cause it to fail?
Is that according to some economic theory for currency?
Whatever that theory is - it does not apply.
Explanation:
https://en.bitcoin.it/wiki/Deflationary_spiral2) Yes, most people hoard, but some spend.
Those who spend are enough to gave it growth.
Being able to transfer value electronically, creates market by itself
3) 80k transactions a day is hardly "nothing"
Not Mainstream=Not real -> It is correct for "standard" currency.
But Bitcoin is not standard, it is not "default" currency of any state
Therefore, requirement of being "mainstream" does not apply.
In general, it would seem that your professors are applying the same conditions to Bitcoin as to "government issued" currency.
It is not. And because it is not, most of current economic theories, regarding currencies, do not apply to Bitcoin.
I think the word "currency" triggers a set of prejudice limitations in their heads.
I would rather use "electronic value storage and transfer system" instead of currency.
That would instantly nullify their "growth", "adaptation", "deflation" claims.
Because how do these claims apply to the "electronic value storage and transfer system" (EVSTS) as opposed to "currency"?
Does the EVSTS need to be mainstream to succeed?
Does the EVSTS need to grow to succeed?
Does the EVSTS need all of its members sending money all the time?