Century of the Self
I think the Adam Curtis documentary 'Century of the Self' does a great job of explaining, indirectly, the Apple religion thing. Its premise is that psychoanalysts in the fifties, led by Freud, defined human desires as blind, uncontrollable things which advertisers quickly found they could play off. It wasn't very subtle - there are plenty of hilarious '50s adverts to back this up - and when people started to reject the technique and proclaim individuality the advertisers found that they could still sell goods by appealing to that individuality: by imbuing the essence of a 'lifestyle' into the product people could demonstrate their individuality by way of that lifestyle: A is into the environment and drives a Prius, while B is clearly a suit, evidenced by the Benz. As different as their values might be they both paid money for their cars and are proud of what they say about them. A positive end-result for Toyota and MB, and a process we call 'branding' and accept as a normal part of life.
And that's exactly what Apple, and many others, do. The adverts, the blogs, Steve Jobs himself are all promoting a way of life that you can be proud to advertise to people around you. The reason the haters hate apple so much is because their ad agency is particularly good at this lifestyle marketing thing and every person on here with an opinion one way or the other is able to conjure up an image in their mind of a mac user. The users identify strongly with this image while the haters, for whatever reason, reject it. The actual demographics of mac users probably vary wildly from the stereotype, however, a testament to how well the psychoanalysts have abstracted positive associations into that stereotype: so the brickie with the iPhone has it because 'it just works' or 'it's cool' and that's more important to him than 'but the cost of that simplicity is reduced configurability' or whatever. The fact is that their ad agency's analysts and statisticians (ironically probably using windows pcs to run their SPSS analyses on) have identified that more people are into 'it just works' than 'I want to install an RFC2324 client on it'.
The point is that marketing a product based on lifestyle attachments is a technique used by firms that want to increase sales and thence return a profit. That's their only motivation, and some of us buy into the lifestyle and defend it because it resonates with our beliefs while others reject the marketing philosophy in favour of making an informed choice about the most functional product. Thus the difference between the fanbois and the haters, and the strength of feeling in the particular case of Apple, is actually down to acceptance/rejection of the lifestyle marketing technique rather than the actual products.
To call this a religious effect is to miss the point that, actually, religions are doing the same thing. By promoting a way of life which people are proud to demonstrate to others - by wearing special headgear or an icon on a necklace - the organisers get followers and thence money. Hence also why opinion is so divided between those who worship and those who don't: it's really about whether you view that kind of association-based promotion as manipulation or not.