A crowded train tires you on the way to work and disgusts your begining of day. It robs you of your motivation as well. Crowded train has a lot of demerit. However, does Crowded train bring all of people demerit? 
At a station way to way, lots people get off a crowded train and there are empty seats. You can sit and the train changes uncomfortable space into comfortable space to your station. You should sit for comfortable space until lots people get into the train. Whether seat is empty or not decides to make your way comfortable or uncomfortable.
満員電車が誰にとっても不快とは限らないんですよね
できれば、乗りたくはないですが