> A single word or a short phrase may be enclosed in quotation marks to indicate ironic use.
Normally, yes. But the primary use of quotation marks is to quote - in a direct response to something someone wrote, you come across as either dishonest or stupid if you claim to be using them ironically.
When I read gergles's comment, it was clear to me that he was describing a class of sentiment, and not directly quoting who he replied to. The manner in which he did it is, to me, idiomatic English.
Normally, yes. But the primary use of quotation marks is to quote - in a direct response to something someone wrote, you come across as either dishonest or stupid if you claim to be using them ironically.