Wait a minute, does the +1/+1 stack? If it does it's the only buff in the entire game that can buff your entire field with, several times! I don't know what you are all so pessimistic about but it seems pretty powerful to me. Combine this with water's excellent stalling and Flooding can EXPLODE your damage!
Of course it can be countered. Which is only to be expected if you can get such ridiculous burst damage. If it really turns out to be useless though, removing "the creatures cannot attack this turn" would make it much, much more useful.