While I understand your frustration about the iPad getting short changed (and completely agree), your logic is flawed.
A good example is the Galaxy S3. The S3 may never receive an OS upgrade. Samsung (and a few other companies) make their products "obsolete" the day they come out. There's no guarantee the S3 will get 4.1 Jelly Bean, which is something Apple would never allow to happen.
Secondly, The 3GS has 256mb RAM and it will get iOS 6. The iPad runs as smooth as it ever did on iOS 5. It's still a worthwhile tablet.
The year the iPad came out, it was much faster than any Android tablet I used, regardless of how much RAM other tablets had. It's about hardware and software being optimized for each other, not about specs.
The iPad 1 showed its RAM weakness not long after I bought it.