Because weapons CONVERGE and fire together in MWO!!!
In TT (and MWT), each weapon you fire are calculated to hit individually so they may not all hit and then when they do, they are calculated on where they hit individually as well, so they may not all hit on the same spot like in MWO alpha strike. This means that in TT and MWT, damage are more spread out even on an alpha strike than MWO, which makes the game last as long as they did.
If MWO did not triple armor values, the game would be extremely short and would also lose even more of the TT feel.
Along the same line, I think thats the reason for not having DHS2.0 either. That would make laser weapons fire more often together ON THE SAME SPOT, which once again makes the game too quick and lose the TT feel.
DHS2.0 and normal armor values would be TT values, in fact, many weapons would also be TT values, if weapons did not fire and converge the way they did in MWO and all previous mechwarrior games. Convergence and alpha strike in MWO is why MWO cannot stick to TT rules without breaking gameplay. So for all you purists out there, I hope this shed some light on the situation.
Just my 2 C-bills worth.
Edited by Pr8Dator, 20 January 2013 - 08:14 PM.