How much more would it have cost to put an extra 256MB in the original iPad? Apple has more money in the bank than they know what to do with; over $100B. It might be a better use of the money to give a little extra RAM to make their devices run better.
Apple didn't get that money taking low margins on hardware. Overall this probably helps their new iPad sales, the vocal minority complain and everyone else probably either stays on ios5 or upgrades.
