Reasons why iOS sucks: App store monopoly, crappy memory management, no hardware freedom, read-only devices
That's really it. If you're a power user, like most of the HNers, then Android tends to be much more attractive. My ASUS Transformer Prime with keyboard dock might be the the best piece of hardware I've ever owned. I think ICS multitasking is the best I've ever seen. I've owned no less than 3 iOS devices, and I can see how they're great for the layperson who is maybe just learning to use computers for the first time, but I can't use one for 10 minutes without being frustrated with a thought like "Is that app still running in the background?" or "Why can't I customize the way this works?"
But then, that just proves I'm not 90% of the Tablet market. I don't fault Apple for going after the lowest common denominator, but doing so means there devices are of no use to me.