What I have detected in this thread and in the other recent similar thread is a cultural divide. I am not trying to be judgmental of anyone, and I don't like to stereotype (but any cultural observation is, of course, stereotyping in a sense), but here are my observations:
Brits tend to be rules followers. They are less likely to question rules, but rather enforce and follow them to a T. The BA agents are given a simple set of rules, and they follow them. Period. BA customers understand the rules; they don't question them; and they don't expect exceptions to be granted. This is clear in knifeandfork's statement in his post: "As we say in London, rules is rules."
Americans, on the other hand (and I am an American and this is true of me), view rules more as suggestions. If we can justify to ourselves and others why an exception to a rule should be made, we will vary from the rule, and we will expect others to allow us to. As can often be seen on the AA board, AA customers spend a lot of effort trying to convince AA agents why their extra guests should be allowed in the lounge, why they shouldn't be charged the fees for changing a ticket, why they should get the upgrade they're not entitled to, etc. Many Americans have a "it doesn't hurt to ask" attitude about these things.
(Again, I'm not being judgemental of anyone. This is just my observation.)
Am I on to something here?
BTW, as I indicated in the other thread, I have no problem with strict enforcement of a rule such as "only one guest." I have a problem with strict enforcement of the "no card, no admittance" rule, given that there probably are lots of easy ways to verify one's entitlement to enter. That said, I have been taught by this board that the rule is strictly enforced, so I make sure always to have my card.