Yes you're right. But I think the point still stands. There are other examples.

If your point is that capitalism can't deliver something like Stack Overflow then I'm not sure the point does still stand, because clearly it could.

The point is rather that a notable chunk of the the worlds most valuable websites are nonprofits. Despite them receiving considerably less investment than their for profit / venture capital counterparts.

Although non-profit doesn't mean charity. Non-profits simply mean they're income needs to be balanced with their expenses, such as through wasteful (or polarizing) spending in the example of Mozilla.

That is not what non-profit means. It means that the IRS does not tax you. There are many different kinds of non-profits and none of them are required to balance income and expenses -- many save far more than they spend and some spend more than they save, they're simply not pulling profits out for investors.

Thats also not what non profit means. There are many kinds of non-profits and some of them aren't exempt. There is a no tax incentive to non profits that qualify (501c), but the definition is, quite literally, that they can't turn a profit. In other words, excess cash cannot be divied out among its owners.