To me this is a great discussion point for the difference in perspective between the genders.
The key offensive word is "hobby". A child is not a hobby it is a commitment that shouldn't be taken lightly. A child isn't an interchangeable object like a boat or a card, I do hope the personality of the guy speaking about this was in a joking way or that he was a humor oriented person.
Other reasons it could be offensive is one may have people in the group that are unwilfully childless and deeply desire children and here is a person making light of it.
It comes down to reading the room. A shared writer we both follow, Yael, can you imagine how she would feel? I don't know, but I can lay a bet it might strike a hard spot for her (as an example).
It is hard because women have been ignored for so long on so many topics, one has to force a conversation assuming the silent "all" when stating men, instead of "some" with the word.
My view which changed over the years is that true feminists that follow the core that are heteronormative really do love men a lot, and want to create some amazing things, because when a person is fully formed they know what they are missing in themselves and desire to complete their humanity and soul through partner ship with another. Who doesn't want to find their missing puzzle pieces in their soul?
I have abuse by a female babysitter and rape in college by another guy to give me the "golden ticket" [ha] to understanding the shitstorms women deal with. I also had the fun of dealing with a woman's studies feminist in college in the 90's who used strong gendered assumptions when I had issues with intimacy with her post rape.
I then realized there were low value and toxic women just like men. I then realized my feminine spirit was what was protecting me and my anti-men and anti-feminist views were keeping me alive. I fixed that by being a feminist which allowed a reboot of my masculinity and balancing of it all.
So one could say .... feminists "hate" inauthentic men, since they make a mockery of something they love very much.