It's a very dangerous gambit, because the more you buy, the more power you give to the company you're buying, because so much of your wealth is tied up in them,

It's a very dangerous gambit, because the more you buy, the more power you give to the company you're buying, because so much of your wealth is tied up in them, their actions directly affect your wealth without you having any control. It's the same reason the argument that China could crush the US economically by calling in its debt is so wrong. That would deflate the dollar to such a point that China would lose literally a trillion dollars of value. Porche simply forgot how much power they had given away.