I am speaking from a user and consumer perspective and have been trying to push our business to adopt Linux because... it is free. We have 100+ computers that are used to open and view pdf files and occasionally open Excel. It makes a lot of sense to go all Linux. However, our IT guy is not comfortable with that.
Plus, we do use specialized software that would have to be compatible with Linux. Unfortunately, the Linux option wasn't considered when we were shopping around for this type of software. Software that we paid $200K for.
We have three servers that are all running Windows.
That has always been the long pole in the tent.
I am also a MCT and LPIC-3 instructor but never get many people to sign up for my Linux courses.
I ask the Windows Server students how they feel about switching over to Linux; mostly they are afraid to--lack of knowledge.
I do believe it is not that they're stupid; just too busy to learn something new which is no harder than what they already know, but don't know that.