It's not a matter of not having the machinery. The penis is an external organ, like a nose or an ear or a toe or a finger or anything else--you know how they feel and how they act. If one has brothers, or male friends (gay or straight), or male roommates, or has been intimate in any capacity with a man, there are some obvious things that a woman can't help but pick up on.
It's like the film The 40-Year-Old VIrgin who thought a woman's breast felt like a bag of sand, because he had never touched one, or seen one up close.
I've had female friends show surprise that a man who does his Kegel exercises can raise his penis by muscles alone, but aside from that, the rest should be a known quantity.
I heard that an Ob/Gyn can palpate a woman's ovaries by applying pressure downward into her pelvic area while pushing up with a finger in her vagina.
Obviously palpating a testicle is much less involved, and anybody can understand how it's done, since, again, it's an external organ.
Some women are surprised to learn that you can put a fair bit of pressure on a testicle, even more than would crush a grape, but it's only sharp impacts that are super-painful. The point is that I halfway assume that the ovary palpation technique is rubbish because:
a. I've never done it or seen it done,
b. it's an internal organ so I can't observe it directly and I've not sure the anatomy works out,
c. I've never talked to a woman about it (yet),
d. I've never talked to a doctor about it,
e. the source is not reliable/verified.
So there are some things that are easy to find out, some one should just know as a matter of course, and others one should be suspect of pending reasonable verification.