This is now managed with drugs, just like someone who lost their leg has their "balance issues" managed with a false limb. I don't think anyone would condone blocking entry to a country because that person had lost a leg in the past.
The decision was appalling, and the fact that it is clear that Canada is giving up private medical records to US authorities is disgusting.
A false limb? There could be a bomb in there! Oh, Noes! And what makes you think the Canadians "gave up" the records? More likely, the American just took them.