He was adding humor.
The black belt had his stat growth stretched across 99 levels.. so a lvl 50 DoS Black Belt is equal to a lvl 20~ NES/PS1 Black belt.
While a lvl 50 DoS Fighter is equal to maybe a 35~ NES/PS1 Fighter.
They messed up a little on his absorb, evade, hitrate, and other things.. overall he grows much slower, can't get as high damage/absorb/evade/etc.. as he could in NES/PS1, and generally gets outclassed by far by thief in DoS, who gains more base hits along with the mages as well...
(Everyone is usually getting 3-4hits by lvl 20 if memory serves.. or sooner... and thief is getting 3-4 hits at like level 8~)
Just from memory and a short consensus...
(this is just early on, they seem to pull back in line after leveing extensively)
Thief hitrate(number of hits)..... tripled it
Mages hitrate.... doubled it
Black belt crit rate.....halved it
Black belt stat growth... halved it.
It may not be that extensive, but you see a pattern... they stretched out BB, making him a little weaker, and much slower to grow, while increasing the hitrate of every other class except fighter in the early game.