“A better source of humour are the shared gripes that most workers face.” Why not “is”?

Question

This excerpt is from the Economist. The sentence "A better source of humour are the shared gripes that most workers face." Confuses me.

Of course, humour can be used, even by non-managers, in a cruel or condescending way. What one man may mean as a laddish joke comes across to womenas a disrespectful put-down. A better source of humour are the shared gripes that most workers face. Everyone can appreciate a quip about the cramped commuter trains, the officious security guard, the sluggish lifts or the dodgy canteenfood. In that sense, workers can feel they are all (bar the security guard) “in it together”. This helps create team spirit and relieve stress.

I suppose "are" here is quite strange and it should be replaced by "is" because humour is an uncountable noun.

Answer 1

It is true that “humor” is an uncountable noun in modern English, but that is irrelevant as to why the plural form of “are” is odd. The obvious subject of the sentence is the singular “source” and so requires the singular verb “is.”

That is not all that is odd about the sentence. At least in American usage, “gripes” are complaints and are expressed rather than faced.

It would be great if you quoted more of the surrounding sentences. Possibly, it makes sense in context, but, in isolation, it looks close to illiterate.

Answer 2

More context would help, but if this is taken as subject verb inversion, the conjugation makes sense. The subject of "are" is "the shared gripes". Written in standard order, it would be "The shared gripes that most workers face are a better source of humour." Compare to "More important is where we will get the money". The subject of "is" is "where we will get the money", not "More important".