Warsaw Will - well said.

I don't get why this confounds Americans so much. They have no problem (at least, as far as I know) substituting the plural pronoun 'they' for various collective nouns, acknowledging that context sometimes implies the plural. They also give sports teams plural sounding names, apparently with no concern for the fact it is still a single entity.
I think you hit the nail on the proverbial when you said it comes down to an American preference for formal agreement rubbing up against a Brit preference for notional agreement (or vice versa, more often than not).
I'm a lover of the English language, and feel like vomiting through my nostrils at the rather rigid view of grammar and language held by many. I'm far more impressed by a person's overall 'command' of a language than by grammatical accuracy (as a rule).

The idea of languages having 'rules' (in the strict sense of the word) is rather amusing, as though you run the risk of being escorted off the premises for improper grammar usage, or being banned from further conversations.

Anyhoo, I thought it a good point well-made, and thought I'd say as much.

Cheerio