Definitely not critical! A person can (and many do) live full and happy lives without children, even if they are desperately wanted... comparing it to denying someone life-saving medical treatment is like calling a skink an anaconda- ridiculous!
Interestingly, a friend was telling me about a dr she knows that is vehemently against IVF- his reasoning is that if two beings cannot procreate together, there is a reason for that- those two children were just not MEANT to have children together for whatever medical/genetic reason (dr's reasoning- not mine!) and by doing IVF, they are weakening the gene pool. This dr is also an IVF baby, incidentally.
And slightly off track... there used to be a school of thought a few years ago that IVF children might have trouble having their own children, and so would have to use IVF, and so would their children and so on and so forth... I'd be interested to hear whether or not that is still the current school of thought on the matter!
Either way- it's for no one else to judge on whether you use IVF, or turkey baster, or yanno.. any other method of conception in the struggle to become pregnant... (I always ask the kids at school who complain/comment on others actions "and how does it affect you?" and 9/10 they cannot give me a proper reason) so to all your friends, I would just say "and how does it affect you?"