Actually, they'll be competing against men their entire lives for jobs and opportunities, and life won't always be fair.
Um. Okay. completely irrelevant to the point, but do go on.
Okay, let's look at this statement. Before the 1970's, there were almost no women's athletics in College. Why? No one was really interested in them. The colleges gave out big fat juicy scholarships to men because they could get a return on investment on some of that. = i.e. ticket sales, merchandising, etc.
Then some feminists agitated for Title IX, and suddenly, all the colleges had to start handing out bags of money for athletics scholarships for girls. Which sounds great, except those scholarships were paid for by students who worked their way through college with minimum wage jobs like I did, so maybe not so much. But it did what it was supposed to do, it got girls into athletics. So there wouldn't have been a "good thing" to ruin if it weren't for liberals to start with.
Not that a few trans women in sports would actually ruin much of anything. Transgender women are only .15% of the population, compared to the 49.85% who are cisgendered women. Statistically, if you are going to be beaten out for that sweet, sweet scholarship money, it's going to be by another woman who was born that way.