I may be too young for this because I hadn't heard it til recently, but did anyone call anyone (or was aware of people calling anyone, if you're too embarrased to admit it) a Christy Brown? Where and when was this? Just interested.
The only Christy Brown I know was an Irish writer born with cerberal palsy who wrote 'My Left Foot', made into a film and I think he was played by Daniel Day Lewis. I take it you mean name calling in a derogotary way? Has this taken from calling people spastics (as was common when I was a kid)?
Interesting question, since I haven't heard this phrase, but in 1981, we cruelly called someone a "Joey" after Joey Deacon who appeared on Blue Peter. There were other Spastic related comments being thrown around. In fact the Spastic Society had to change it's name to Scope because of people taking the mickey.
As nice example of childrens misunderstanding, around the time that the spastic society changed its name we started using 'scopes' as an insult. I remember someone telling me very earnestly "no, you can't call people spastics anymore". The insult lived on, just rebranded.
As far as I'm aware there isn't any irony. Just a lack of success with the rebranding of the Spastic Society, we understood the name was changed, but just interpreted it as a change of the derogatory word.