That is like saying a child should enjoy their punishment when bad...
Subs are punished when they misbehave... when they show lack of respect to their Dom/me and have to be corrected ..
In a proper s/D relationship that is a good portion for it's existence... To Obey.. To respect.. And never ever defy his/hers Dom/mes wishes or wants... If a sub does this against her Dom/me... especially under contract or agreement.. then it is cause for punishment that will change the out look and response of the subs actions so it will never happen again... Thus it must be something the sub does not like... and if severe enough .. it should push their hard limits...
In this statement the keyword is "Role Play" It is play and not true punishment.. It is an act that is supposed to be fun as it is play..
Maybe that will help you understand the difference between the two punishments samm.. I hope i have helped and that others will give you their opinion..
Just my opinion
hugs
snow