Bantios, your response belies the era in which the majority of the younger generation of pilots have the bulk of their experience....dare I say glass......and trust me there are inherent traps in that. Older and wiser (no disrespect intended) drivers have many rules of thumb that continue to keep them out of the poo. FMC's are fallable, trust me on this.....and when your pretty electric jet becomes a dark cabin on a stormy night after the BTB's failed to contain the short on the Right AC bus and all of a sudden you no longer have an FMC.....or much else for that matter.....what the hell are you going to do......quick mate.....time is one thing you do not have a lot of.
One example if I may, the SQ400 out of Auckland.....if they knew an approximate V2 using a rule of thumb for their BRW then it may prompt them to question the FMC produced Vspeeds (which came as a result of incorrect input of ZFW for TOW producing figures for a weight some 100T below actual BRW.....easy to do as the 74 has such a varied weight range.....you can litterally T/O one day at 240T and the next at 385T) Every time I walk onto the flight deck I dial an approx V2 in the MCP as a safe guard that tiredness/time zones and numerous other distractions do not result in the above ever being repeated on my flight deck.
Think outside the box......one day it may save your life and that of your passengers.
(Melbourne......DJ perhaps?)