Yeah but he had a gas mask didn't he?
He had to make sure nothing stopped the microwave emitter and train from reaching the middle of the city to the hub under Wayne Enterprises, especially with Batman on his tail.
It's not like Talia and Bane who seemed suicidal and culty.
Plus, for me that's the weakest element of Batman Begins, the third act. After Arkham Asylum and before "rebuild it brick for brick". The whole microwave emitter plot was one of my biggest problems with the film.
But it looks great compared to,
"we goin' to africa to get diamonds fo dagget and pick up doctah pavels to help make a bomb. we gonna make dagget king of Wayne Enterprises after we use his cement explosives (like Mission Impossible chewing gun explosives) but really miranta tart is in chahge. Then we goin' to plunge da stock mahket even tho everyone knows we sabotaged it. we gonna have pavel pull da cell then we gonna release da black gate prisoners and pretend dis is a revolutionary of sorts. we gonna kill da pittsburgh steelers too. on top of dis we gonna break betmen financially, physically and emotionally by sending him to the same prison me and my gurl escaped from. yeah, he ain't gonna escape, I just left him with a prison doctor that can heal anything. BUT DA BOMB DOESN'T GO OFF UNTIL 5 MONTHS FROM NOW OR UNTIL DA TRIGGAMAN PULLS THE SLOW AND SILENT KNIFE. HAHAHA WE BAAAAAAD. oh ****, Batman just broke mah mask."