The only argument I've put forward is that when some hack journo uses vague statements like "sources say" then they're most likely taking a stab in the dark.
Yes and No.
A journalist will never give up their source, because 1) they'll lose access to all their sources if they throw one under the bus, and 2) they'll lose access to all their sources if they throw one under the bus.
It does give them BS immunity though. Because the genuine hacks, of which it appears that there are a number nowadays, can use the "sources say" to write anything, including blatant lies to fuel an agenda. But the problem is, that true anonymous sources do exist, and will never be referred to openly. So, it makes it difficult to sift through the falsehoods and to know what to trust.