I think "economics" does not begin to explain why this is the way it is. I think it is far more complicated than "well, companies have no financial incentive to develop this."
Condoms are not just birth control. They are protection from STDs.
Hormonal birth control has a lot of side effects. If a man has certain side effects, sex can simply not happen. Then, what's the point? You can skip the drugs and just not have sex. Done.
Many people are incredibly uncomfortable discussing birth control in "casual sex"/dating type situations. It is far easier to assume it is on her or use a condom.
The heat the testicles method provides no proof it is being practiced and no means to show he is temporarily sterile. Plus another comment in this discussion indicates it was eventually shown to cause permanent damage.
Her giggling comments about sex suggest she has no clue what sex is like for a great many people. Her saying that the withdrawal method is something where he has to do it but she has to not protest because it feels too good -- a lot of women do not have orgasms from penetration. There is enormous amounts of shitty stuff that goes on behind closed doors for a great many couples and this woman sounds like she has no clue what the landscape looks like in that regard.
I am just flabbergasted.