If bitcoin is to succeed, then these points must be argued against. But that rarely happens. The poster will be simply called a troll, a few ad hominen attacks on him and then put on a stupid, pointless ignore list.
The sad thing is that even the most rabid bitcoiners find it difficult to string a few words together into a logical argument to defend bitcoin. Thats what worries me most.
There's a world of difference between genuine argument, discussion, debate, etc., and humoring someone with a proven track record of shameless concern-trolling.
The misguided "professor" in question is an inveterate Buttcoiner through and through, believes that Bitcoin is inherently a scam, yet feigns airs of curiosity and moderation to suck people into his egotistical troll web. He has very predictable patterns of disingenuously just "asking questions" as troll bait to setup pre-conceived wall of text rants.
It's impossible to really engage this kind of mentality because he bombards you with a sheer volume of pointless text that is too exhausting for anyone sincere to deal with, whereas the troll revels in this imaginary domination of people on the internet on the basis of nothing. You can confront this kind of person with facts and arguments all you want, and he repays you with passive-aggressive self-deprecation. No amount of rationalization for this behavior as some kind of self-appointed do-gooder obligation overcomes the natural reaction that such a toxic participant can fuck right off.