It would work, but i just wanted to add consistency with the search validator field, which has the div selector. 

div.ui-input-text.bb-text-valid + .bb-validation-icon, div.ui-input-search.bb-text-valid + .bb-validation-icon {
	background-image: url('images_bb/input_validation.png');
}

They both work without the div selector. So to keep consistency we could remove the div selector on both? ..