If I were paying for such tutoring, I'd want my faults clearly highlighted by the tutor without holding back or tippy toeing around for fear of bruising my ego. Without such honest clear criticism (obviously combined with practical approaches to address weaknesses), I'd feel I'd have wasted my cash and might as well just be singing songs in a strictly social setting.

Others might be more 'delicate' (especially if brand new to singing) and prefer a less direct approach than me though ;-)