Here are some relevant facts...
Tom Kirby
GW C.E,O and chairman stated
GW '..is in the buisness of selling toy soldiers to children...'
The release schedule is set by
GW sales department .NOT the studio.
The
GW game development team is told to write rules to 'inspire sales of new models.'
The fact the
40k rule set is such a mess, over complicated and counter intuitive.(Despite the game play being comparatively simple.)
Means the development team is at a massive disavantage at trying to arrive at any sort of balance.(Not aided by minimal play testing.)
And so often fail to make the rules 'inspiring' enough for competetive players to take.(Do not judge the level of power needed accurately enough.)
However, they do seem to believe enough 'cool sounding special rules' will inspire the rest of the customers!