If you have a rigorous, detailed theory of Friendliness, you presumably also know that creating an Unfriendly AI is suicide and won't do it. If one competitor in the race doesn't have the Friendliness theory or the understanding of why it's important, that's a serious problem, but I don't see any programmer who understands Friendliness deliberately leaving it out.

Also, what little I know about browser design suggests that, say, supporting the blink tag is an extra chunk of code that gets added on later, possibly with a few deeper changes to existing code. Friendliness, on the other hand, is something built into every part of the system--you can't just leave it out and plan to patch it in later, even if you're clueless enough to think that's a good idea.