I don't think it does. I am a potential buyer, and I could care less about the "openness" of the product.
I actually see it as a good thing more than bad however. With a PC, every time I run a new program, or get an upgrade, buy a new device, etc, I never know what to expect. With Apple, there's no question. It almost feels "safe".
I don't feel safe with Apple. They deleted all my music from my iPod without asking just because I inserted it into the wrong Mac. I guess Apple fans will be able to explain to me how this is really an ease of use feature.
I'll never give up my MBP, but I think the issues you're speaking of have more to do with the OS (cough Windows) then they do with the openness of the PC itself.
I actually see it as a good thing more than bad however. With a PC, every time I run a new program, or get an upgrade, buy a new device, etc, I never know what to expect. With Apple, there's no question. It almost feels "safe".