Aslong as we get some profits with this well nothing wrong for selling on whatever price it is we have different decisions and surely our ideas will not meet and be the same and i believe those peoples who bought on 200$ level is sold their coins already for a long time. Remember their are long time stability when price goes on 500-600$ up and surely people sold what they got and i am one of those seller for that price before.
You are right, active trader never mind about potential profits of future. They will always look for the profits which are possible within the day.
Always on one can be sure about future hence booking profits at any desired level before it will become late must be a meaningful action. Maybe those decisions turn wrong in future but we cannot be sure they again did not enter into bitcoin after seeing prices were running through $800 levels.