> Ever since I saw that, every single time I wait for people getting off a crowded train, I wonder "Why?". Cost reasons. Wherever you adopt this, you need two

> Ever since I saw that, every single time I wait for people getting off a crowded train, I wonder "Why?". Cost reasons. Wherever you adopt this, you need two platforms to serve a train instead of one. Not saying it doesn't make sense to do, just that someone probably sat down and did a cost/benefit calculation.