Three--It appears that much (not all) of the complaining directed at MoS over the "destruction" stems from the fact that these particular filmmakers chose not to portray Superman in a Silver Age/Christopher Reeve style. I like Silver Age comics. I have a bunch of them and I read them with my 8 year old son. I also like the Reeve Superman films (well, the first two, anyway) and have watched them with my 8 year old son (who also likes them). But I can appreciate a different take on the character--one I will not watch with my son until he's a lot older than 8 years old. Much rather that than simply "lather, rinse, repeat" of Silver Age/Reeve Superman. But, different strokes for different folks.
You've likely hit upon something there with me, anyway. I looked forward to taking my kids to see MoS. I wanted them to enjoy it as much, or more, as they had Superman Returns - particularly sequences like the airplane rescue.
After watching MoS I realized they probably wouldn't enjoy it but for a few minutes here and there. It wasn't what I expected and that certainly colored my reaction.
Personally it seemed to me the battle at the end was reaching disaster porn levels rather than being grittier or some new take - but that's my opinion.