I suppose if it's a dead donor who explicitly gave her permission for her womb to be used, then that's fine. Why not? Personally, I wouldn't want to ever donate my womb, and I'm uncertain about my other organs - what if they go to someone who's a terrible person? There's a fairly high chance of that, especially if they go to a man.
With live womb donors, I think there's far too much risk, and too many potential negatives (such as prolapse, early menopause, dementia risk, etc) just so that a woman can have a biological child. It's a frivolous, luxury surgery that doesn't improve the recipient's health or physical quality of life at all.
I suppose if people want to do it, it's not much different to cosmetic surgeries...and yet there's something very body-horror-ish about it - that a particular organ which only women have, can be 'farmed' from other women.