I'm with elnan. Sort of like these people who wear their pants almost falling off their rear ends. I want to say "PULL UP YOUR PANTS". I'm not sure what the deal is; it does NOT look good and it is not a fashion statement - to me anyway.
A friend of mine years ago was waiting to pick up her grandkids after school and while waiting, saw a young man crossing the parking lot and his pants fell to his ankles; (personally, I'd have gotten out of the car and laughed at him SO loudly). She said he looked around, bent over and pulled his pants up (how far, I don't know) and kept walking. Wonder if he learned his lesson. And BUY A BELT for the sake of the rest of us! And use it. Funny things people do.
BUT I do understand wanting to lengthen the top. I have that issue with some tops too. AND the sleeves that they are now making on women's t-shirts. It's like having a wedgie in the arm pits (to me). I HATE them. For me they are not comfortable. I'd like to find a nice way to lengthen them a couple of inches so they are wearable and look nice. So I keep wearing my old ones. More comfortable.