i guess thats the difference between just play and actual D/s.
in a D/s relationship there can be an actual 'sharing' of ideas, like limits, rules, and what is expected during training. a Dom/me who is aware of these limits may push them, but its after a space of time and presumably are doing so because They know how the sub will react and can account for it to make it safe.
playing, though, isn't as moderated by rules and protocol. it's the same as a vanilla one night stand- how much detailed thought was put into the turn on/off's of the other person in a one night stand?
as Belgarold said- the "D"s who immediately start making orders and pushing limits of a sub aren't actual Dominants- they simply enjoy rough sex and have watched too much porn, and are basing their actions on exploiting somebody who they presume is weaker- a submissive. these people aren't deserving of respect. leave immediately.