"There was a rumour that it was due to a particular nipple cream in the 1980's that had peanut oil in which was giving babies exposure to peanut antigens. I don't know how true that is, probably not very." not true at all. In fact the thought process is that it's because of a lack of exposure to nut products during pregnancy/early life hence why the nut advice in pregnancy has now changed to suggest that women should eat nut products in order to expose their babies to them.
And if nuts should be banned then so should dairy, bananas, kiwi fruit, all of which carry potential for severe allergic reactions.
And obviously the banning of nuts means the need to ban all nut based products, so no chocolate bars permitted on flights either, that should take care of some of the dairy as well.
People talk easily about a wish to ban for nuts because as a general rule most people aren't actually that affected by the lack of a packet of peanuts in their daily routine. But no-one would uphold a similar ban on dairy products which can also have the same kinds of reactions, because it would be much harder to expect people to go without cheese for instance, or dairy based spreads, or to request that babies not be fed milk on a plane, and yet the life of the dairy allergic person is surely just as valid as that of the nut-allergic one? And if not, why not?