Theres plenty of ebook stores that do well on Android.. Kindle, Aldiko, & Nook all do well and I use all of them when there are deals, just like I use the Amazon and Google marketplace. When deals appear on apps/books I like, I buy. The content is more valuable than the actual reader.
On webOS (myself, wife, daughter) I had the option of requiring a password every time an app was purchased or just letting my 13 year old daughter rack up whatever credit card charges she felt like on her phone. I don't consider it a PITA to enter a password, I consider it a security feature. I am shocked that you imply that android does not have such a requirement and I feel further vindicated in choosing webOS over android.