The reason why is TP efficiency.

Note I have 1.1 for all direct damage, as dragon kick only applies to direct attacks, not DoT ticks. All other buffs are "normalized" out.

TP efficiency of ToD: 25*10 + 20*1.1 = 272 per 80 = 3.4 p/tp
TP efficiency of FR : 20*6 + 100*1.1 = 230 per 80 = 2.875 p/tp
TP efficiency of ID : 180*1.1 = 198 per 70 = 2.83 p/tp

TP efficiency of BS (crit) > Twin > SP = 566.5 per 170 = 3.33 p/tp
...

etc.

Demo is obviously one of your highest tp efficiencies, at over 4.8 p/tp if counting only itself, at around 3.58 p/tp if counting combo.

ToD should be kept up as it is more efficient than your main combo.

Everything else is significantly worse.