You can imagine a typical bell curve distribution in terms of performance, yeah? So, the male bell curve is shifted along the x-axis a little more than the female bell curve, but a) that doesn't mean that there isn't overlap and b) it's not like being a cat 4 says much about where you're at on the bell curve.

Well, exactly. We know there is some difference, and we only have a vague idea of where we or anyone else that we see on the road lies on that curve. But I would think that any guy who's ridden enough to complete at least 10 mass start races with other competitive and reasonably fit men - and keep at it - would naturally see himself well to the right on that graph of female riders, so unless she's clearly stronger or making more of an effort than he cares to, he's probably going to think he's slacking and maybe needs to pick up the pace. Speaking for myself, if my awareness of my performance is ever alarmed in this way, I just try not to engage in any knee-jerk reaction. But I'm usually not alarmed, I'm usually already aware of how lazy I'm being.

Maybe she should be congratulating the guys for being able to hang with her.

Getting back to the original post, group rides often involve some compromise, stronger riders have to back off a little and weaker riders may have to go out of their comfort zone more often than they'd like. In this particular case the OP had an expectation of an 'endurance' ride. Because it was a small group riding 2-up, it's pretty tough for riders with significantly lower power to keep up unless they stay off the front. This was suggested to the OP but she, for whatever reason, didn't want to compromise and ride in the back.

I think that's the essence of the problem: The OP wanted to ride with the others at her endurance pace but not just sit in, the male riders wanted to ride at their 'endurance' pace not the OPs.

We have some strong women who ride with our group regularly but they spend relatively little time out front. It works fine in a larger group but perhaps a little lonely if there are only 5 in the group and you have to sit in the back row by yourself.

i think that it's been pretty well established that this was not the case, as evidence by both the OP's testimony and the fact that one of the guys blew up and needed a tow.

If pace / drop tolerance wasn't posted prior to the ride, the default assumption should be no drop. However, this is complicated. I've been riding with the people I usually ride with for years and know their strengths and weaknesses well. I generally assess what I know of the people who are going to show up for my group rides. I know if certain people show up, it's going to be fast. If other people accept, I know it might be a bit more leisurely. It's incumbent on every rider to honestly assess their fitness vs. others in the group and proceed accordingly. If you don't know the capabilities of other riders, I'd say you have to be willing to deal with the consequences. If it's a strong group with one weaker rider, I do think it's a bit unfair for the pace of the entire group to be dictated by the slowest rider. There have been rides for me where I'm getting my ass kicked and I have no problem tell the others to just go. I personally don't feel comfortable making people wait for me. This does not seem to be the case in this ride, given that others started to blow up way too early. I'd say it sounds like a possibly inexperienced group.

I sure didn't have time to read more than a dozen posts to this thread, but this sounds like perhaps more of an issue with the specific person who made the invitation.

When I go on a regularly-scheduled ride for the first time, I always come fully-self-sufficient, and with just about no expectation as to whether I will be able to keep up and complete the ride or not.
Experience has taught me that the same applies even when invited by a rider who does the particular ride often.

It seems that after a while, riders show up to most regularly-scheduled rides with clear expectations as to speed/effort and distance/terrain, so I am very careful to not put myself in the position of having to ask for that to change.
I've attended rides where I regularly got dropped for many weeks until I could stay on board for the duration, and there was ultimately satisfaction and training benefit from that. I have known women who went through the exact same process in preparation for a season of long rides and/or racing.

But again, it sounds like the inviter perhaps failed to communicate fully, and then failed to show any concern for your fate on the ride. I am making assumptions there though, based on what I don't actually know about your ride history together, and on many other things.
I would advise to let someone (ride leader) know if you are uncomfortable with the idea of bailing on a ride and making it home in a self-sufficient and safe manner, which of course might depend a lot on the conditions, distance and geographic location of the route. I am not able to say whether or how badly that anyone failed in their responsibility here, as there are just to many things about your situation that I am unaware of, but at least you now have a better idea of what this group and their rides are all about. Thankfully you made it back safely, and I hope not too discouraged. Hopefully also, that you have other rides/groups to choose from.

Don't think that's the case. My example simply goes along with what others were discussing.