Why mechs and not insect like machines?

yeah, maybe their mechs are mechs just because they should resemble the human species, with two legs and all.

 

^^^oooh ok i gotcha ShdwyTemplar
that's a good analogy with the Thors
I think if they had six legged mechs, they would do what I think will be a common Terran strategy once SC2 comes out (depending on build time), which is that Terran players will probably build their Thors closer to the battle or base they are intending to siege
this also is based on the fact that I don't think Thors will fit into dropships