Startups don't win by attacking. They win by transcending.
Another reason mean founders lose is that they can't get the best people to work for them. They can hire people who will put up with them because they need a job. But the best people have other options.
There is also a complementary force at work: if you want to build great things, it helps to be driven by a spirit of benevolence. They may not say so explicitly, but they're usually trying to improve the world. Which means people with a desire to improve the world have a natural advantage.
For most of history success meant control of scarce resources. That is changing. Increasingly the games that matter are not zero-sum. Increasingly you win not by fighting to get control of a scarce resource, but by having new ideas and building new things.