Most people aren't picky about screen resolution, as long as it is in a usable range. Most tablets are in ranges similar to their laptops and desktops, so it suffices.
Apps, kinda the same, as long as they can do what they want. Plus how many are useless barely downloaded apps? But too few apps and people are hindered. I have been hearing that about Windows RT. Too few quality apps for what people want to do. It is also why so many root the nooks. My nontechie mother-in-law was asking me to root her nook Tablet, because there were too few apps in the B&N app store.
Things will change in time, but Microsoft isn't making it easy for themselves. No to mention, but how many surface buyers bought because they expected their Windows apps to work? Once they find out it doesn't, and that you're limited to just the appstore, you'll probably see sales drop, especially since the fanboys will most likely have bought by then.