Agree with your sentiment JT, however the thinking pilot is slowly being regulated out of civil RPT ops. In my time as commercial pilot, flight planning has either been on the back of the fag packet or something electronic fired out by some software.
The variables beyond the legal requirements which rely on experience to judge are the biggest factors concerning flightplanning nowadays. Domestically anyway.
Example. Why bother planning to the nearest 20kg when ATC holding can be anywhere from zero to 25 min on any given SYD arrival.
Having said all that, its a good idea to be aware of all the factors that affect fuel burn and how they might affect you on the day. Keep the study up. Its free and it might just save you some paperwork one day. Or worse.