A bad logo can inhibit a good organization. A logo is intended to be a mental shortcut to past experiences with a brand, hopefully bringing up good feelings. A good logo is distinct, and not generic. A good logo is simple, and not complex. A good logo is appropriate, and not awkward. A good logo is striking, and not bland. A good logo is legally protectable, and not indefensible.
Design is an integral part of branding. Good design both create positive experiences and links that goodwill back to the brand.