I beg to differ, I have an adult female bp that went from eating ft to only accepting live. I tried to get her to eat ft again and she refused food for 8 months until I offered live, took it in an instant. I suppose I could have tried ft another 8 months, but honestly I got sick of watching her lose weight.
I certainly prefer ft for convenience and safety, but there are snakes that will only take live, ball pythons in particular it seems.