Why do pros not build their additional markets near the ally one to avoid a useless empty trip?

[Shakal5089]

Isn’t it generally considered exploit and bug abuse?

For example Battle of Africa 2, 3vs3 tournament that happened in May 2020 had a rule specifically against it:

1. It’s not allowed to intentionally place markets in both ends of a trade route in order to increase the trade income by trading with adjacent markets or skip the first trip.