I have certainly heard other people say they've known people with hair that never got beyond about APL or BSL even when they never, ever cut it. I suppose it is possible to have a really short terminal length.
I also find mine tapers quite dramatically after about APL too... the longest my hair has been was close to waist (then again, I'm a very short person, so it may only have been BSL on others) and even back then I'm pretty sure it was very thin at the ends.
I guess I am just going to see what happens with my hair! I've decided to not cut for a year, and then have a small trim (I may do a micro trim half way through the year... which will be late July), and just... see what happens, I guess?! If I find my hair really doesn't have a long terminal length and thicken up EVER, I will probably keep it trimmed to where it looks decent. I really don't like the idea of having straggly ends where some hairs get quite long and the rest do not. I'm not talking about nice fairytale ends here... I'm talking about having just random long hairs and really uneven looking ends at a fairly short length!