Really gets my goat, this.
Hear it so much in RL (my mother in particular is a keen jealousy accuser). See it on here a lot too.
For example woman A tells woman B that woman C was a bit off with her during a discussion on BFing/family size/schooling issues/winter boots, woman B says "oh she's just jealous"
Now, obviously people can be jealous on occasion but without anything to suggest it other than a difference of opinion why would anyone jump to this conclusion?
Its bizarre and reductive and dismissive and assumes a real lack of depth about the person being accused of it. She might be a right tosser, a bigot, ignorant, vindictive, thick, she might -just possibly- simply have a differing opinion! It strikes me as very lazy to write it off as jealousy.
In my experience this is pretty much something said by women, to women, about women. Why such little faith in the ability of others to have real, solid opinions?
I wonder if its a form of trying to reassure the other person? like 'oh dont worry that she disagrees with your decision/opinion...its only because you are so fab!' but surely no one wants such petty meaningless reassurance? And if it was reassurance you wanted you'd want it about the actual subject you were talking about rather than some vague assumption that dismisses the other persons opinion as irrelevant cos she's 'just jealous' anyway?