Religion-y Type Things In The Pokemon World:

To Haruka, BREW... has the same standing as a legendary Pokemon in her mind.

It serves its given purpose without fail and to a extremely high standard; humans cannot bend it to their will; whenever humans attempt to interfere with it, disaster occurs. It is neither benevolent nor malicious, and exists solely to carry out its purpose to through whatever means necessary.

tl;dr, she trusts it to do its job nigh-perfectly, and that means the people it has picked can't actually 'mess up' in the scheme of things. Everything has a purpose, even when they can't see it.