It is within the scope of human nature to be curious, so I cannot deny a temptation to play... but it is also within human nature to beg forgiveness rather than permission. This is why touching is inherently dangerous, so although gentle "interaction" with marine life is not so horrible it is the example that the educated set that makes the difference. All those touching life --most particularly the instructors-- had better be clarifying their position on the dives, so the newbies aren't learning bad habits.
You may think this is too strict, but that student 40ft away may not think at all... and learn a lifetime of selfish behavior from you regardless of your motives. An instructor who is sloppy about this is probably sloppy about some other important issues as well.