The mistake your father makes, and I mean this with all respect, is that he mistakenly places too great an emphasis on what he thinks customers will want and not enough on what they are willing to spend money on.
I think my feelings on it are a pretty good example.
I don't particularly like the price and proprietary platforms, but the bottom line is that the product, taken as a whole, is a wonderful little piece of technology.
I don't care if Apple limits my choices if the choices they do give me are ones i want anyway.
For example, if I really want Filet Mignon, cooked rare, with steamed asparagus, a baked potato and bernaise sauce cooked really well, and there is a restaurant that provides me with that, I don't care if they don't also offer Grilled Halibut or Broiled pheasant.
And if the food is to my liking, I also don't care if I could get something similar a little more cheaply somewhere else or with some different side dishes.
If I'm the type of diner who needs lots of choices and flexibility, I should probably just go somewhere else and enjoy my choices there.
But to wonder why someone enjoys what they like, seems a bit silly.
Apple manages to put out products that a lot of people really like. Not everyone will like them as much, and so the lack of choice or high pricing or other issues will sour them on the products. Nothing wrong with that. To each his own.