I guess it depends on what kind of investor you are.
If you're holding MS stock long-term, and you plan to gradually shift away from equities as you near retirement and then gradually liquidate your holdings to fund your retirement, juicing the stock in the short term does nothing for you.
If you're holding short-term, then you also need to sell the stock after it gets juiced, so that you can move your capital to not-yet-juiced stocks.
Missed a point above - that for said short-term investor... that strategy doesn't actually work, since a "sell high buy low" strategy on individual stocks is outperformed by just holding ETFs long-term.
So really, which investors does short-term stock juicing benefit? Insider traders, I guess.