Why? Because word of mouth only gets you so far in the internet era. People discover new businesses—even local business—via Bing, Google, and Yahoo. The days when they'd just look you up in the yellow pages are long gone. If you don't have a sharable website address, your chances of building online word of mouth via social networking plummet, too. In other words, no website, no discoverability, no money. Of course, web hosting isn't just for businesses. You may want to host a personal website or blog, too. Either way, the services here have you covered.
On the topic of dedicated hosting, many web hosting services also offer managed hosting. This type of hosting sees the web host act as your IT department, handling a server's maintenance and upkeep. This hosting option is something that you'd typically find with dedicated servers, so it's a business-centric addition. Naturally, it adds a few bucks to the hosting cost, but nothing that should break the bank if you have the resources for a dedicated server.