There is nothing inherent in knockoff that says it doesn't work. That would be a fake.
While I can find definitions that call it "an inferior copy" (link), that's not the point. Common usage has made it so that people will assume things about the quality or efficacy of the medication when certain words are used. Even if a word is technically correct, perceptions about the word can make it a bad choice.
Often when patents expire and other options emerge, they are called "generics" or "store brand" versions. Those terms don't carry the negative associations.
Yea please, this is my primary method for seeing updates about KDE