There are plenty of great female Judo players out there. In my brief time in Judo, I was frequently thrown by a variety of female Judoka from teenagers to adults.
Judo though is indeed harder on the body than BJJ and less forgiving of injuries. Instead of a clear uke-nage separation like in Aikido, you and your partner compete to see who can throw who first. There is always a chance if you will land on the mat with your toe/foot/elbow/hand/etc in the wrong position - the level of skill you will need to control your body while it is midair to avoid injury is much higher than in Aikido.
It is common for older Judoka to specialize in matwork and give up throwing altogether, because of accumulated hip injury. The last Judo club I trained at was run by a fairly old gentleman - I think he was old enough to have trained with Gene Lebell. Anyway, he had hip replacement surgery and so could no longer demonstrate throws. This club hosted a workshop taught by high-ranking Judoka visiting from the Kodokan in Japan - one of them was a little woman whose specialty was matwork (though her throwing skills are not exactly chopped liver as we say in the US). Her teacher, as you may have guessed by now, was a matwork specialist because he, too, was unable to throw after a lifetime of injuries.
Thus my observation, based admittedly on limited experience, is that BJJ offers better lifetime value than Judo.. If you're going to end up specializing in groundwork in your old age, you might well be training in the art that is better suited to that, instead of waiting to be forced into that specialization. Helio Gracie was still sparring and submitting his sons at age 95.
Oh no, don't get me wrong, I am not insinuating that women cannot be good at Judo nor that they should not undertake it, I am questioning his assertation, not voicing my belief. I have seen some footage of excellent female judoka. I believe the injury points are valid though likewise you can say many people suffer from injury problems with Aikido as well - particularly the knees, as myself - so that they even stop suwari waza entirely or do not take certain ukemi. Is it more likely to be injured in Judo? Yes. Does BJJ also come with it's own risks of injury? (Quite possibly greater than that of Aikido) Also yes. Even if my own athleticism were not up to scratch for the art, is that a reason to avoid it? Should nobody that is unfit take up a martial art because it will be difficult? In any case, learning that art will improve your own fitness, even in Aikido at first my quads were not up to long stretches of suwari waza and not used to the amount of strain, but they have grown stronger and now do not present any issue.
If we are looking at lifetime value, Aikido itself offers one of the longest durations in terms of until what age you can remain a practitioner. Does that mean we should only train at Aikido because sooner or later other arts would have to be dropped? Can you not improve yourself by training with sincerity and determination while you are young and fit? Even if you eventually have to give those practices up, you will learn a great many things on the path that will apply to both. If the only thing that matters is how kind or soft the art is to your body in return perhaps Yoshinkan practitioners should give up their style and find another.