Considering that people are rushing to work (It's not just a current concern; This was a concern alluded in the Gemarah in several places, which became part of the concept of torach tzibbur), why was Shacharit made the longest of the 3 daily prayers?
O.C., among other sources mentions the importance of kavana during prayers. Proper kavana usually means extra time to concentrate on the meaning of the words and make them more meaningful. In actuality, many Shacharit minyanim are rushed so that people can get to their trains, buses, etc. and arrive at work on time. One could, perhaps, argue that if Shacharit were shorter, it may not need to be as rushed. Or, perhaps, Ma'ariv should have been made the longest prayer when people are not rushing to work.
Note: - I've mention my reasoning as to why I think it shouldn't be. However, your answer need not focus on this reason. There was prob. some impetus to making Shacharit the longest of the 3, regardless.