Are you referring to this statement from Jebb's comment?

"…I believe all are true."

The key word is "believe." I can understand how you would interpret that statement as an assertion of fact. However, it is also reasonable to understand it as I did, as a belief that may or may not be an assertion of fact. It could equally be understood as an assertion of possibilities. I believe both interpretations are reasonable.

In your original comment, you cited this statement...

"...young men are having very little sex..."

...spoken by your colleague, and you responded with...

"...that also means het women are also lonely and not having sex...".

I read those statements as: "...young men are having very little sex..." (therefore) "...that also means het women are also lonely and not having sex...".

It is phrased as a logical conclusion. Since it is a logical conclusion it is reasonable and valid to characterize it as logically flawed if one finds that to be the case. Doing so does not necessarily constitute a dismissive phrase used against women. Although it may, at times be used that way, it can be a legitimate evaluation of a logical conclusion. I have never noticed it used as a gratuitously dismissive phrase against women, but I may not have been paying attention.

Jebb's logic is also flawed. Women having sex outside their age group would mean that men are also having sex outside their age group. It has no bearing on the number of people of either sex who are having sex. If women are having sex with each other, it would follow that a large number of women could be having sex, while few men are. However, in actuality, only a small number of women are having sex with each other, not enough to affect the availability of sex for men.

If a large number of women were having sex with a small number of men, then a few men would be having lots of sex and the rest would have little. Most women would remain unchosen by the few men, and so would experience a deficit of sexual opportunity. That is sound logic.

Many possibilities could explain why women and men are experiencing a deficit of sexual opportunity. A male deficit does not necessarily imply a female deficit (or vice versa).

Saying your logic is flawed does not imply that you are personally flawed.😎