I have to say I disagree. Parenting is a joint effort, and affects both people equally (but in different ways).

I would agree that biologically, women are most fertile in their twenties. But your argument that "Oh, he should just go for it now because you are ready," isn't very fair, and seems to indicate that her readiness is all that matters in the decision. Instead, I would recommend to OP that she seek counselling with her SO, so that they can have a guided discussion about what exactly they want to have in place/accomplished by the time they begin trying to get pregnant. A rational counselor will be able to help the couple decide if his concerns are reasonable (i.e. "I want a house before we have a kid," may not be a reasonable expectation depending on financial status, quality of living, and/or geographical location. However, a reasonable concern is something like, "I would like more time to work on us and become stronger in our relationship before adding in a very crazy element," depending on the relationship).

I also don't believe that just because he is putting it off, means that he doesn't want kids at all. But I do agree that he may have fears of which he is not even aware, that I'm sure can be addressed in counselling. Or, perhaps he just has an idea in his head of precisely how he wants things to be in his life before he has a kid, and it should be up to both of you to decide if these are true concerns, or if he is finding reasons to delay because of any underlying fears.

I know the baby bug can give a really strong bite, but you are setting a great precedent in your relationship by working on the situation together, and by compromising. Successful relationships begin with great precedents, and continue with consistency. Having a baby is a very important decision that should be made together, when both people feel comfortable with the decision (note: comfortable does not mean "ready", since "ready" is a very subjective term).