I always hear people cite this statistic and I’m never sure what they’re getting at with it.

Surely we’re in agreement that this is a good thing, right? That a shortage of organ donors due to the donors not dying is a good thing. Sometimes it feels like people are suggesting otherwise and I can’t fathom the logic.

I think there's a slightly charitable reading of that opinion. Replacement organs are already in short supply, it's a real problem. By "bigger problem" he's referring to bigger than it already is, not that organ recipients dying is a worse problem than all of the organ donors dying like the status quo. It's a good problem to have, but it's still something the medical profession is going to have to grapple with when their supply dries up.