So, they've changed everything but the main aerodynamics
Bigger and smaller aero bits are changed, breadboards are changed, diffuser is changed, gearbox is changed, exhaust position is changed, suspension is changed but shape of the nose, chassis and sidepods is almost untouched as if represented a masterpiece in 2006 while in even one year ago it looked like it was from 3 or 4 years ago.
I don't see the logic in trying to get performance by tuning additional aero bits while you leave main object like sidepods ridiculously square relative to other f1 cars even though Toyota has several times bigger budget than some teams. TF107 looks as they've used no CFD and wind tunnel at all but just tweaked here and there. Another thing evolution of unsuccessfully car is logical move but evolution of unsuccessful car despite having all the budget in the world isn't logical.
Line up TF140, TF105, TF106, TF107 and compare evolution with evolution that happened at other teams and you'll understand why people think that Toyota makes funny F1 cars relative to budget they have. Compare differences of TF104 with TF107 and those between Renault R24 and R26 or Ferrari F2004 and F248.
Perhaps the changes made on TF107 are big but in F1 they are racing against other teams who have already made much more radical changes years ago so TF107 might be big evolution only relative to TF106 not to contemporary elite of F1 like Renault or Ferrari.
Being conservative is exactly why they'll never win any championship (with not much brighter prospects for race win) unless some lucky rain or collision related incident doesn't help them.