You may not be comfortable, but it's a common enough thing. It typically happens when there are long queues at gigs, theatres, cinemas and so on. I'm pretty sure I've seen it at the Natural History Museum where I recall the toilet facilities being inadequate. Normally there is some assertive woman who leads the charge. My mother has definitely joined the line of women going to the gents. I've never seen any protest.
Completely aside... this does happen, although it is almost always limited to crowded events. And there's a very good reason why - ther've even been some studies on it.
In short... the actual facility availability isn't equal. Sure, there are probably the same number of rooms labeled "mens" and labeled" womens"... but with each of those facilities, the actual number of receptacles isn't even. Frequently, the male restroom will have only slightly fewer stalls with toilets, and will have at least as many urinals as they have stalls. Female restrooms only have stalls. Stalls take up more space, but in most buildings, the male and female restrooms have the same square footage. That means that for example, an average theater restroom for females may have six stalls, while the male theater restroom has four stalls and six urinals. That allows up to ten males to use the restroom at a time, whereas only six females can do so.
And that's before we take into consideration the time involvement, compliments of anatomy. If all a male has to do is pee, they can use the urinal. It's generally a quick unzip, pull out, pee, insert, zip up operation. For a female, pants need to be partially removed or skirts pulled up, then undergarments need to be partially removed - add more time if the female is wearing tights or hose. Then that clothing needs to be put back on. The entire process of removing clothing from the area of fire is longer for females than it is for males.
So the net result is that female restrooms have fewer receptacles than male restrooms do, AND females need longer in order to use those receptacles on average.
So even if a building has the same number of rooms set aside for male and female toileting... the actual utility of those rooms is very different.