There's a strategy I see very commonly deployed with open source software: you release your code as open source, knowing full well that competitors will come along and take business from you using your own software. And it works brilliantly.

Why does this make sense? Because as long as they are using your code, you are always going to be one step ahead, and always have a strategic advantage. As long as your marketing and other aspects are competent you only need to be slightly better to get the lions share of the business, and having a controlled but viable entity in second place will keep more competitors from entering the space.

I see a similar aspect to giving your competitors advice.