Without the Shattered Empire I hear that The Mentak Coalition is one of the worst, if not worst race. But this is just rumors, can someone please shed some light as to why some people opt to remove them from the random draw?

Maybe they are not the worst arec at alll, but surely the Mentak need a little upgrade.

First of all both their special abilites are conditioned by the other players, especially the ambush ability is close to useless if you are the attacker since the defender decides the order of pre-combat effects. Plus your initial set-up in terms of units/technologies is not that good.