When you have a good website, it will position your content in search engines, which means it will position your company, your services or your products, which means that while you sleep there will be people reading your content, looking at the photos you uploaded, using your contact form or paying you for what you sell (if you have an E-commerce)
A bad website, will request you from a lot of attention to fix things, to enhance your content, to make changes
A bad website, will request you from a lot of attention to fix things, to enhance your content, to make changes, to fix bugs... it won't position your content in SE, there won't be people looking at it while you sleep or won't bring you new customers.
Some of our customers come to us after dealing with this scenario and come to us frustrated and tired, they really don't think a website will do any good for them or their companies... they soon find out that was just a bad experience, that a website can really work for them.