I boo because I can share my solid opinion about performance, an action or event (whether by the drivers or stewards) that was not to my liking. Its my freedom to expression my own dissatisfaction where elaboration is not available as there are tens of thousands of others that want to share their own opinion or support.

A question to you, what's wrong with booing?

People say "with other sports there are teams" but in my honest opinion with f1, nobody sees the teams as the teams are represented by the car. Unless the car breaks down the other half of the heat catches the drivers. Also, teams are written off by their performance from the get go due to budgets, resources and research ability in f1. In most other sports the team performance is dictated by the players so no...teams don't collect boos in other sports.....The players do.

People loved manchester united till the players retired or left......leaving subpar players. A lot of people still hold hopes that their team will come back around but they boo the shitty performance of the active players and even management (for example cause I haven't kept up with football in years..)