each team has a limited supply of barricades being 10 per team, they are very useful for blocking the enemies path which can be used for defending the flag, or helping to escape when trying to score - but some people login their alt accounts to the opposite team to use up all 10 barricades outside of the base in obscure locations, so their main account doesn't have to deal with people defending against them.

it's mostly driven by inflated egos and rivalry between some regular players but it's really boring for everyone else who likes to play because it's fun and challenging - a lot of these players also use 3rd party clients to make certain parts of the minigame easier for them, personally i think it's because they lack confidence within themselves to learn the "complex" mechanics of the minigame but it could be something else.