The issue lies with alarms set using the repeat function and not those set by date, where your reasoning is valid. Set an alarm for a time and a repeat by days of the week and the set time wanders onwards with each snooze invocation and stays there if the alarm gets "unticked". If it is stopped at the snooze interval ring, then it reverts to the original set time (as it should).

So, the issue actually is one of how to interrupt a snooze cycle without unticking the alarm.

Or should one simply let it ring (until "stop" if one is around, or until a timeout)? Does the latter stop the snooze alarm ringing again? If it does, I assume the original time is kept.