It bothers me because what other people use actually does affect me.
I am in general unhappy when I have to deal with Apple fanatics.
1) It is their way or the highway. For example, each and every Apple fanatic that I know refuses to use anything other than Facetime. Skype, no. Viber, no. Other procucts? No to all of them. How does that affect me? Either I am left out or I have to fork over money for Apple products.
2) ".*" files. Ever work with someone with an Apple product? Now your disk drive, flash drive, Dropbox folder, etc is cluttered with thousands of ".*" files. Yes, each is small, but now your computer is slower scanning thousands of these useless files and your drive's usable space is now smaller, etc.
3) General refusal to take simple steps. I've had several projects (work and personal) where I relied on an Apple user to do things. These projects crashed and burned because the Apple user got to a Word ".doc" file and refused to open it (and didn't forward it on to people who would open it). They only open ".pdf" files. Word file viewers are free, just take the 1 minute to download it. But no, they refuse to open the critical file that tells us the deadline and so we miss it and the project ends miserably.
4) Putting a square plug into a round hole. This may be minor, but I just cringe when I see my boss with terrible eyesight and thumbs the size of a baseball bat struggle with his Apple 5S. I tell him every day that he needs a 6+ or just about any Android so he can see the text and press the buttons. But, no, I have to wait 5 minutes for him to get anything to function then I can progress with whatever was urgent. All that time, I get to hear how Apple is so great and that the 5S is the best thing ever and that my large Android screen with vivid bright colors, high resolution, and easy to read text is terrible. Just because your favorite company made a product, doesn't mean that product is right for you.
I am generally unhappy with AMD-only users.
1) Not because AMD products are terrible, but because AMD products are almost always put into terrible computers. Manufacturers of computers think of AMD as the budget line, so they skimp on motherboards, memory, etc. Basically they pair the processor with the worst possible components. Then the AMD users, who shop solely for price, buy only the worst computers out of that already bad selection. Now at work I'm stuck with a 5 year old worst computer with the worst components ever made with USB ports that are all fried and can't even open the Solidwork files that I rely on. And Microsoft Visual Studio 2012 takes 30 seconds from the time I hit a keyboard button until that letter appears on the screen. Yes, the IT department's insistance on AMD only does affect me.
2) Being computer literate, I get to diagnose problems for my family (I refuse friend requests). That means that every time their computer with worst possible components has a problem, it comes back to me. Buying Intel wouldn't be a guaranteed fix, but it certainly gives them a chance to have a reliable motherboard and a powersupply with enough power for their computer.
In general, I am unhappy with any general brand fanatic.
1) I have to hear about how great that brand is every single time I see that person.
2) I have to hear about how great that brand is every single time I see that person.
3) I have to hear about how great that brand is every single time I see that person.
4) I have to hear about how great that brand is every single time I see that person.
5) I have to hear how that product is the best thing ever built and best that will ever be built (until the next thing comes out from that company).
etc.