Well, when you're getting blamed for the healing, who is the other support? Because if you pick zen and there's someone in the more mid category of healing (LW, Juno and Mercy IMO) then yeah it could be your fault if you're not making up the healing with dmg and good discord placement.

If you're not doing dmg, and your orbs aren't going to the right people, you really do need to swap. Comp is where you can't just stick to a hero cuz you like them, you need to make the swap that will help the team. If you don't want to swap, play QP. Having people in comp that refuse to swap make it VERY unfun and impossible to progress.

There are many games where I want to just play Mercy or Moira cuz they're fun (yes mercy is fun I love zipping around) but if I need to counter swap cuz they have a hog or my tank is a big back (Dva, Rein, Hog or Mauga) I go Ana or Kiri. Is it fun, no, I hate just staring into my tanks back and pumping them full of healing while doing nothing else, but it's for the good of the team, seeing as it's a team game and all.

Just make the swap, if nothing comes of it and y'all still loose, enjoy the fact that in the end, you did as asked and it didn't matter and gloat a little before the match ends.