Since the update to version 1.1 it has become much more closer to the quality of the Firefox one. However, there are some limitations in Chrome so unless that changes ABP in Firefox will always provide the better adblocking experience.
Extensions using experimental API cannot be uploaded to Chrome's add-on gallery. Anyway, the currently available experimental API won't help us much. Only interesting thing is the undocumented pop-ups API which should help improve our user interface.
I don't think it is a design choice, it merely doesn't seem to be a priority (and you can hardly blame Google devs for that). Frankly, the whole extension API doesn't seem to be a priority - I have yet to see a single bug being resolved as fixed.