The problem is that we _do_ want uniqueness validator, but we don't want _remote_ uniqueness validator.

Config statement `disabled_validators` disables stated remote validators unconditionally, whether they are enabled during `construct_validators` or not. That was taking effect in middleware (throwing 500's when hitting disabled validator) and, as of now, in javascript (halting requests to that validators), because not everyone needs that. Also it's a bit slow.

If you want to disable specific validator altogether, you should use `validate: {validator_name: false}`, I guess.