Re: GPL == security?
Compare that to a BSD license for example where two companies may be running the same software but one has access to patches the other does not.
This might work occasionally but it actually makes more work for the "cheater" because they have to work harder to keep their patched version in sync with an upstream source. This is why open source is valuable in and of itself and doesn't need any pseudo-philosophical justification. I think Google's record of kicking back changes on the various projects it uses is a good example for this, but other companies understand it equally well.
Where a company does have some secret sauce that does provide some significant commercial advantage over the open source variant, then obviously they have to weigh up the costs of integration against the revenues generated by the commercial advantage.