Especially in the case of the Surface - it's the first version of the product! The original iOS and Android devices all had crappy or non-existant app stores when they were launched, and were plagued with problems and limitations.
Similarly, for the right use-cases iPad Mini and the Nexus tablets are epic, and many people adore them.
What's so great about Surface besides its design and build material? I don't mean to knock on those. I think they are great, but that doesn't equal that the product overall is great. Windows RT is performing very poorly on an high-end ARM chip (don't want to imagine how it would perform on an older dual core ARM chip, or god forbid a single core one) compared to the true mobile operating systems like Android and iOS, and its app store is virtually non-existent. Office on it is also an exercise in frustration.
The price is also too high for what it offers. Even if the build of materials is exactly the same as the iPad 4 (I think it's lower), that doesn't mean it should cost exactly the same as an iPad 4. Because it offers lower value than an iPad (think ecosystem, brand, etc). I also don't think it's acceptable for a $500+ product to have such a low resolution anymore. And don't tell me it has an "extra 16 GB". It doesn't. It only has 17 free GB of storage.
You should go play with one in person. It is a really neat tablet experience. Spec for spec it may not appear that competitive, but the user experience is really slick. Snapping apps side by side (have your music on a small pane, and another app on the larger one), the app switching model, side swipes to pull up menus, and the look and feel of Metro are all really refreshing takes on a touch os.
Almost all the complaints I have heard relate to the apps, particularly third party apps. The OS itself everyone seems to agree runs very smoothly. Considering it was only released last Friday, I think we should give them a little more time to mature.
Some people like the "big phone" style tablets, but personally I'm much more interested in a tablet that is a true multitasking full-fat device. Surface is imperfect, but it's a great step in the right direction.
For some people it's better value than the iPad, for some its worse.
Especially in the case of the Surface - it's the first version of the product! The original iOS and Android devices all had crappy or non-existant app stores when they were launched, and were plagued with problems and limitations.
Similarly, for the right use-cases iPad Mini and the Nexus tablets are epic, and many people adore them.