The only reason that Bitcoin can ever have quasi-universal acceptance (valuation) is if it can become a currency, and it can't because it is being valued for a delusion about it being rare with a companion delusion about it being (or becoming) a currency which is an antithesis of the first delusion.
The usefulness of Bitcoin as a cheaper and less regulated money transfer is very ephemeral. The Spiraling Transaction Fees design of Bitcoin will kill the cheapness over time, as well the government regulation is coming and the spy agencies are recording all your transfers and identities and taxman cometh later to destroy the delusion ex post facto with nice penalties and treble rates.
You were a terrorist trying to move your money outside of the country or to another person avoiding the $600 1099 reporting requirement?! How dare you. Show your paperwork. Ah we find your paperwork is lacking. Confiscated. Done.
28%. Wow we are making headway in the consciousness of the audience.
The key characteristics of anything that resembles a ponzi or pyramid scheme are:
1. No intrinsic value, it is all a willful delusion of the participants.
2. Viral adoption as deluded participants scurry to induce greater fools by word-of-mouth.
Physical gold investment most certainly has an intrinsic value and you will always have that rarity and tangible value (that you can hold in your hand) and thus it can't go to 0. Bitcoins are not rare, because anyone can create an altcoin, and the only thing holding people into Bitcoin is a) the poor quality of the competitors thus far, b) the delusion that Bitcoin is something that it isn't (it isn't a currency), c) the delusion that the limited network effects thus far are a barrier to a great altcoin, d) the delusion that Bitcoin doesn't have technological flaws which doom it, e.g. Transactions Withholding Attack and the Spiraling Transactions Fees.
Shares on major markets usually have intrinsic value and they almost never have the ability to sell like a virus, because most people are inherently skeptical of pink sheets shares because they have many examples of failure.
Whereas, "this is new, it has never happened before, this is the greatest new innovation" is what spreads like a virus.
I see so many of these schemes, such as "this health system will restore your vitality" pyramid schemes, and there is no intrinsic value. It is just herbs you could buy for 1/1000 the price in bulk.
If you want to defeat this logic of mine, your only chance is to argue that Bitcoin has an intrinsic value and justify your willful, collective (what I strongly believe to be) delusion.
Arguing for pedantic, narrow definitions of such schemes makes you look desperate. Actually argue the point.
You can try to argue against:
Read this entire thread:
Problem With Altcoins