I suspect that Ted wasn't consulted about the change in giving.
A good rule is that you cannot make suggestions about gift exchanges that benefit you (or your family unit) at the expense of other people. So the LW could have suggested that they exchange gifts family to family, or told Ted that he didn't need to get a gift for the adults, or suggested not exchanging all. But they picked the solution that benefited their families (tons of presents for their kids), while Ted and wife don't get anything at all.
And yeah, there can be something isolating about sitting there watching other people tear into tons of presents when you don't get anything at all. Particularly if there's no thank-yous involved. The worst case of this is for the single, childless family member, who is not only expected to get presents for all the kids, but doesn't have *anyone* to give them presents. Even in the kids present scenario, I'll bet the spouses exchange gifts, and the kids get something for the parents, neither of which the singleton has.
I would be curious to know the dynamics of the family in general - for example, is there a trend of everything being all about the kids, and the couple without them being shoved off to the side as less important?