maybe, and maybe not. it's true, anything made by microsoft is automatically a magnet for hackers and such. but that doesn't equate to something not made by microsoft being any more or less vulnerable.

a vast majority of security problems are found by computing security companies, organizations or educational institutes, who target different programs/vendors equally. their aim is not to bring bad press to anyone, just to help protect the general public by making the problems known. if you know about the problem, you're more likely to be able to avoid it. if the problem is publicly announced, the makers of the software do get some shit for it, but then they're more likely to fix it - and fix it *fast*