WordPress is by far the most popular content management system (CMS); it is easy to use and there are hundreds of free templates, called themes, and plugins to change the blog's appearance and extend its functionality. Sites hosted on WordPress are free, with a paid option to add your own domain name.
Free themes are ideal for someone keeping a personal blog; no one expects a casual blogger to design a custom theme. Nor do they expect someone to buy a domain when a WordPress subdomian is free. However, a business, a brand or someone who keeps a blog to monetize it with AdSense, should give their visitors more than a standard, boring stock theme.
If you run a website or blog to earn money, your visitors deserve an aesthetically pleasing site with original graphics. For a one-time fee, you could have a developer design a theme for you that represents your brand perfectly, if you cannot create a custom template yourself. While there are hundreds of free, safe to use themes on WordPress.com, only a few will probably be suitable for your niche. With WordPress powering 28 percent of the sites on the Internet, there a good chance that one or more of your competitors will have the same free theme.
Developers generally do not like WordPress because every plugin that a client wants added slow their site down and makes it load slowly. Additionally, WordPress is not the most secure CMS. It's open source; anyone can download the code and find a vulnerability to exploit, although half of WordPress hacks come from plugins.
WordPress is great for a blogging platform, but when people try to use it as an e-commerce platform or anything else but a blog, it does not perform as well as expected. If you have a business, pay a developer to design a custom website for you that will wow your visitors.