Won't say I got marked as anything as the reddit post is pure hypothesis, but I've also encountered this. I have been playing Moira a LOT and won quite a few matches and even end the game with about 2-4 golds (elims and obj elims, along with healing, and usually with an obj time on top of it). She's damn near designed for that with an orb that can tag every enemy in a team fight. Most of the games were with smart people who know how to strafe around and avoid a lot of avoidable damage, and my healing orb could usually be reserved for myself (usually with teammates too, just be smart about the bounce).
Now, I'm encountering mostly flanker style players or 3-4 support main comps, or Rein's that suicide charge, Winston suicide jumps, etc. I change my healer depending on comp. My playstyle hasn't gotten worse, and I've actually IMPROVED as a support player; but my team members seriously seem to have downs right now. People die 1v2 while trying to flank while we have a 5v4 on point (that we are losing because Rein won't quit swing his hammer at DVa that's S keying away and leaving us all exposed to a sniper and 76), and the flanker starts bitching that we lost because Moira is a terrible healer. I've had other games with Widows that stand in the open and fire at us unopposed that I've had to chase away as either Mercy or Moira, which obviously means I can't heal, simply because no one would shoot at her and were lobbing Hanzo arrows into a Rein shield. Am I happy I had to do that as Support? No, but at least the second support was responsive and knew to focus healing themselves when I announced I was doing that, trying to get our damage to apply SOME pressure. That's the quality of team members I am getting the last couple of days.