It was more that those relationships didn't seem to be happy and long-lived ones, but were always confronted with some trauma of some kind.
Which is true of most relationships in fiction, period. I think the OP's complaint was that where prominent same-sex relationships were concerned, the trauma in question seemed to tend disproportionately toward the demise of one of the partners. I'm not sure whether the statistics would really bear that out, though, or if there's a large enough sample set to distinguish a genuine trend from a random fluctuation.
That's fair. But I also think that the idea that the trope of the "Dead Gay" or the violently-ended same-sex relationship is an unfortunately common trope found in fiction (often in the past employed because of a need to express disapproval of same-sex relationships -- The Children's Hour
, for instance), and that as such writers should consider making a special attempt on some occasions to avoid such tropes, is also valid.
In other words -- no malice intended, everyone believes in equality, but sometimes depictions unintentionally coincide with fiction tropes that were once used in an oppressive manner, and it's good to be aware of it and to avoid it at least some of the time for future reference. A minor criticism of something that's unintentional, not an accusation of any prejudice.