I can't tell if you're being condescending intentionally or not, but I'm not sure how you could get the impression that I don't understand what "buyback" means. Obviously it comes from the company; otherwise it's just a regular stock sale that doesn't need any additional descriptor.
The issue to me is that the division between "money companies get from selling their shares" and "money companies get from selling their products" is artificial; whether it gets taxed differently is a procedural issue, not something that inherently defines what "value" is. When the value of something is only from selling it again in the future, it's inherently only valuable as long as there's someone else to pass it onto to sell it again later. Sticking the company in the middle of passing it along doesn't magically change whether it's sensible or not. That's what I mean by "effectively a Ponzi scheme", even if it's not strictly one in the definitional sense. The same arguments for why a Ponzi scheme is undesirable apply.
The issue to me is that the division between "money companies get from selling their shares" and "money companies get from selling their products" is artificial; whether it gets taxed differently is a procedural issue, not something that inherently defines what "value" is. When the value of something is only from selling it again in the future, it's inherently only valuable as long as there's someone else to pass it onto to sell it again later. Sticking the company in the middle of passing it along doesn't magically change whether it's sensible or not. That's what I mean by "effectively a Ponzi scheme", even if it's not strictly one in the definitional sense. The same arguments for why a Ponzi scheme is undesirable apply.