Draft horses are a kind of horse, and horse's hooves should look like.... horses hooves!
They are built and function the same way as any ungulate's hoof. Are subject to the same pressures & distortions when they're not managed well.
While I do believe it's vastly more about 'deed' than 'breed' - environmental factors, rather than genetics are the major influence on any hooves - drafties, arabs and standardbreds are among the breeds which innately tend to have better, stronger feet
. So it should
be easier getting/retaining healthy, well functioning hooves on them.
Unfortunately, drafties, who people generally realise don't mature until 'late' are often neglected for longer in their early years. Combined with the normal trimming only 6-8 weekly, combined with a drafty generally being a lot more work for a farrier, even if they are well maintained - & too many aren't & many farriers are too lazy to do a good job - which is too little for most horses, their feet are then 'prone' to flaring, cracking, 'dropped' flat soles, etc.
I'd hazard a guess that these people you speak of just have no clue how to rehabilitate deformed feet, or perhaps even as to what hooves are meant to look like. Possibly they've been ill advised by some... ill advised farrier. So they're using the excuse - or spouting someone else's excuse - that they're doing it on purpose.