why would you compare 80-90 years and hundreds of years to begin with? really, why? ofc after saying goodbye to a lot of people your thinking change.
Because the argument was about "loss". Some of them had lost pretty everyone in their family and it didn't particularly make them suicidal (or at least not that they showed it). Additional decades or centuries wouldn't change much about that as everyone is already gone anyway.
Boredom after centuries might be different (yet how could you find the last century of rapid technological advancement boring?!) but I don't really see the argument over losing people close to you. We all live with that. Got parents, grandparents? Siblings? Friends? Well, they are all going to die, unless you die first. It won't make you suicidal, I can practically guarantee it.
So I really don't see why anyone automatically assumes that immortality is some sort of curse. I'd take it in a heartbeat. ^^