Just my two cents. If you are using Bootstrap 3 then I would just add an extra style into your own site’s stylesheet which controls the text-left style of the control-label.
If you were to add text-left to the label, by default there is another style which overrides this .form-horizontal .control-label. So if you add:
.form-horizontal .control-label.text-left{
text-align: left;
}
Then the built in text-left style is applied to the label correctly.