You can never win a dispute by arguing rationally. When I took debate class I learned that an emotional argument will trump a rational one every time and my almost 60 years of life experience tells me this is true. But the best argument of all is an emotional argument disguised as a rational argument because people want to appear to be rational. (This is why debate class turned out to be the single most useful thing I took in college.)
So what you really need to do is to find out what emaotionsemotions are important to the stakeholders and couch your argument in terms of what they are emotionally attached to. Note this isn't necessarynecessarily emotions like jealousy or love but what factors make them want Apple vicevs Microsoft. Listen to the reasons they give and look for the emotional bias behind them. Then couch your argument back so that what looks like the rational choice also seems to meet their emotional need.
For instance, some of those people really love Apple because it is what the "cool kids" use, so make them understnd that in your world the cool kids prefer Microsoft or Unix or whatever you are trying to sell to them. Part of doing that is acknoledgingacknowledging that yes Apple products are great for what they use them for (validating their choices because if they use it to be cool, they want others to see them as cool) but for this purpose, the big guys in the industry (name dropping is key for these people) prefer...Then give the rational reasons why (making it an emotional and rational argument, the one that trumps everything.
The trick is listening to them long enough to understand the emotional attachment they have to their choice, validating that in some circumstances this is the best choice and then attaching the same emotional argument to your preferred choice, then following up with the rational arguments so they can look good telling this to their superiors.
The example I gave is a common emotion attached to the fanboy mind set, but it not the only one. That is why you really have to get to know them and understand why they like what they like before you can effectively drive a change. It might be a motivation to keep their boss happy and thehythey know he loves his iPad. It might be they had a bad experience with the brand you like 20 years ago. It might be they are afraid of how hard it wouoldwould be to learn something new or a hundreds of other reasons. Fear is an espciallyespecially powerful emotion, so really look for that one.