It's called tanking. The best way to discourage it is with a mutili-season win requirement. One of my worlds has a four season target of 55/120/185/260. My other two worlds have a slightly more challenging four season target of 55/125/195/280. Failure to meet a one season, two season, three season or four season target, you are removed from the world.
If you want to tank . . . you do it at your own risk.