This article is old but seems to miss some key factors. For the record, my sister and I both fall in the age group in question. I am still skiing, but she is not.
As many have said above, when you take a break from skiing for yourself for the pregnancy years + the skiing with kids stage, it is harder to go back to skiing for yourself. In my own marriage, my husband never dropped his high level skiing days, but I dove head first into the "make sure kids are having fun" mindset. It changes how you view skiing. It also inadvertently skews your perception of skiing as work because instead of just having fun yourself (if you are primarily the one wrangling kids), you now associate skiing with all of the work of getting kids to the mountain w equipment, having snacks, and just always being "on" when on the mountain.
As a member of the sandwich generation, I have elderly parent responsibilities that don't always lend itself as much to being unplugged on the mountain.
...But a big one is menopause. I have my hormones figured out by now, but for women who are surprised by physical changes related to perimenopause and menopause, skiing can be hard. The temperature, bathroom break challenges, the muscles involved, muscle soreness, frozen shoulder, the shifting of weight on your body, fatigue and insomnia, foot issues and ski boots, carrying your equipment across the icy parking lot... Andropause does not have the same impact on men.
According to NIH, as of 2018, over 43 percent of American women over 40 are medically obese (not just overweight), with similar percentages in the over 50 age category. Skiing is really hard if you are overweight. Skiing is even harder if you are obese and older. The obesity levels in the US across gender and age groups are rising. That is probably your biggest threat to skiing.
The cost of skiing is a huge deterrent. The cost of the equipment, lift tickets, clothing that isn't really targeted to older female bodies, expensive on mountain food that isn't going to make us feel great after... Women in my age group aren't the target market for skiing. I don't think the industry really cares who has disposable income anymore because younger generations are so comfortable with credit card debt. They care if the customer is happy to pull out the credit card, not if the customer can actually afford it.
Some of us like it enough to keep going. I don't feel old. I plan to be in the age 90+ ski group someday, but the industry doesn't really want us. It is okay. We can still be out there having fun anyway.