How would you feel if you were one of them?

I'd feel pretty upset. A few days in space is no big deal. Months in space is hard on the body, plus you're missing out on months of life on Earth -- maybe you're going to miss the birth of a child or grandchild, or a loved one's death and funeral, or some other big event. And are you getting paid while up there? Are there enough supplies? What if NASA and Boeing finally decide it's OK to return on Starliner, and as you know you basically must then, so now you're risking your life on a vehicle that you have much reason to think is not safe.

It'd be hard not to be hopping mad in private. I'd make the best of it, since there's no other choice, but I would not be happy about it.