A rather nuanced subject, one in which the staff will ultimately take the appropriate feedback here into consideration for their decision. If you want to be heard, it's best to do so in a cordial, logical voice, particularly in regards to the points against the suggestion.
Ultimately, you have to look at problems you present and see if there's a solution.
Splitting the line between sexual and romantic FTB is important, and has been touched on a bit. It's the difference between they kissed and went to bed, and emoting aaall the way too the bed, into the bed, till the point an FTB is necessary.
Some awkwardness about babies has been mentioned. It's not hard, actually. You do what you would have always done when making a story with another person's player character. You send them a tell about the topic of family in the plotline.
In regards to minors being on the server, I was on here around 14 or 16, I can't quite recall, but either way I was quickly met with private offers for Especially Raunchy Play left and right, and to be honest, I kind of doubt a lack of FTB in relation to sexual acts could change what happened. Additionally, you can bet I had parents permission to do whatever I wanted on my computer. And even if I didn't, you can't control teenagers. You can only control their environment.
My first character was asexual, with an at least inclination for romance for the first three-four years of his existence due to my own adolescent things going on. Of course, my experience also comes from being a particularly focused on person by a large population of people who assumed a little too much about my maturing in relation to age.
It's different from the average player run on Lord of the Craft, and from a professional, security mindset, removing "Sexual FTBs" would discourage the probability of the aforementioned undesirable behaviors that violate server rules (Grooming, predator behavior, ERP.) Sure, you can deal with something after it happens. Yes, people are quickly caught for ERP on the server. But my journeys through roleplay communities over the past decade have learned me of the darker perspective this should be regarded with.
To reference an actual story on another game, on a roleplay server, a fourteen year old (who is now much older,) was made victim to one of the situations that the OP wishes to try to prevent. The older individual was held in some high regard to the fourteen year old, and that trust was violated when they transitioned a roleplay session right past what should be an FTB into some really messed up things that are definitely unrealistic kinks, but can be quite traumatic to subject someone to reading.
In those situations, a younger person can literally not know what to do. They were in an environment that was supposed to be a safe place. That can quickly change, and while you an ban the offender, you can't make what happened go away.
Anyway. Because these kinds of discussions call for a side, I support it. Remove sexual FTBs. Approach it in a manner with care.