Not necessarily. Apple certainly doesn't think so, and they're doing a lot better than any other computer manufacturer.
Too many devices and options creates confusion. It's hard for tech-savvy people to understand why that's such a big deal, but for a lot of the general public, it is. They don't know what they want or need, so they a) have to do a lot of research, b) buy something that may be wrong for their needs and then aren't happy, or c) just don't buy anything.
Apple simplifies the choices. This drives many MR users mad because we generally know what we want and need, and we like to be able to pick and choose down to the last feature. But a clean, simple lineup makes life a LOT easier and more appealing for a lot of consumers.
If you like the iphone, you get an iphone. Ok, there are two choices: 3G or 3GS, and 16 GB or 32. But those are simple choices that most people can easily understand (3GS = faster. 32 GB = more space.).
To a not-so-tech-savvy person, android sounds techy (just look at the name!) and complicated. What do you buy? A lot of devices run android, but is it all the same? (no - see the motorola cliq with its motoblur overlay) Do they all run it equally well? (no) Do they all have the same capabilities? (no)
The iphone is simple. You go to an apple store and buy one of two models, which are frankly not that different anyway. You know it will work right because apple designed the hardware and the software. The interface is clean. There's one button to push. It's all but idiot-proof.
If this doesn't sound like a big deal to you, try having a conversation about android with a non-savvy friend or family member and see how they react.