Maybe people just don't like it

Maybe WinPho7 isn't successful because it has few redeeming features. No apps that Android & Apple give you. A completely boring UI you can't change except choosing colours and a chunk of your home screen is lost to an empty bar down the side just to hold a button which you don't need because you can slide across without it. A completely grey mail experience. No flash. No plugins. It can't stream video. You have to hand over your machine to Zune to get ANY content on the device. Which can be useful - recoding of video during upload is cool but the video player is horrible. There's a slider showing progress that doesn't let you slide. I can't get mine to turn off and charge at the same time. It just powers back on. I have to use airplane mode at night. The phone dialer is beyond basic with almost zero address book integration and when I search my address book from the dialer, I get all my facebook contacts who don't have phone numbers. There are no background apps except email so no facebook or twitter alerts or weather updates. You can't send an address book entry via sms/mms/email or anything else and there's no cut-n-paste so the best way is to read it to somebody. How 1980's.

And, if you power it on and then wait too long or do something like hit the windows button before entering your SIM PIN, you're lost. It shows a "pin required" icon that you can't click on. The phone dialer says pin required but there is no button, no menu item, nothing you can do to get the Enter PIN screen back. Either power cycle or get into the settings and go into airplane mode and then out again [BTW if you know a better way, I'd LOVE to know].

Mine's a work phone so I didn't pay for it but I'm considering going back to my HD2 with 6.5 which could actually do things and had heaps of apps available (although nowhere near Android or iOS)

MS chose to go down a new path. It could mimic Android and be fully open or go the iOS closed ecosystem way. It chose the latter. But while iOS has a huge biodiversity in its ecosystem created by an army of fan(boi)s supplying useful and/or fun apps so you don't really care that you have no control, the WinPho7 ecosystem is like being locked all alone in a biodome with a cactus.

Which is a shame, because much of the design of the system has so much promise. Even the simplicity of the interface has many positives.