If one does not think that buy backs are good to begin with, making them as difficult as possible (as was the case before the mid 80s) is preferable to the situation today.
Forced liquidity and the tax implications can absolutely be bad for investors.
If my option is a 5% dividend or a 5% share buy-back, the net-of-taxes benefit of the 5% dividend is 15%-20% less due to capital gains taxes than the share buy-back. The effect with annual compounding over many years is quite material...
> how much of the profit is socialized vs privatized
What does that phrase even mean? It's nonsensical. Whether via buybacks or dividends, money goes from the corporation to its investors. That's why investors invest.