I agree with you. A lot of men just happen to bump into younger women and start dating them. Quite a few of those turn into happy relationships. What I wrote was about those who specifically target younger girls. And sadly, pretty much every woman I ever asked had a ton of stories how she got targeted as a teen or while being in her early 20s.
A woman who's 30 and being approached by a man in his 40s or 50s doesn't seem bad. I would argue that if the fertility is a motivator though, men who are 40 and especially 50 aren't as fertile as younger men, because male fertility starts to reduce around 40 or slightly after. Therefore, men approaching much younger women who are more fertile makes sense, but you have to admit that's hypocritical. Also, most people don't have a lot of kids these days, so the fertility shouldn't even be a concern. And finally, a man who is 40-50 often already have a child/kids and may not be very motivated to have more children, unlike guys who are 30-to-40, quite a few of whom are childless. So, while the topic of fertility is fair and deserves attention, it can also be an excuse.