It's a lot more complicated than this. For example, money can be borrowed using stock as collateral and spent. Companies can and do also issue more stock. There are also indirect effects, for example investors putting money in new ventures.

Either way the economy is not zero sum game where there's a fixed amount of money. If the stock market grows there is more money. That money reflects future expectations discounted to today but it's still more money.

On the original question, how does Ballmer being very wealthy impacts the rest of us, there is no easy answer. It depends on what he does with his money. It can be neutral, positive, or negative. The sentiment though seems to be mostly driven by jealousy and a sense of unfairness. It's in fashion these days (in some circles) to hate the "rich" (which is basically anyone better off than yourself more or less).