Deciding on what your next site should be built in can be tricky. Hopefully you have a good developer willing to walk you through all your options. If not and you're relying on the great Google to help you, you're probably going to be bombarded with both WordPress fanatics telling you how amazing it is and those saying it's the worst blogging platform ever invented. Regardless, 19% of websites built on the internet are using WordPress and growing. That's a huge number. Think about it- 1 in 5 sites is now using this content management system.
My absolute favorite part about WordPress is the plugins. Need a social media widget? No problem. How about a twitter feed? Done. This is the primary reason I would recommend WordPress to anyone. The community is extremely large and there are a wealth of free plugins as well as premium ones for just about anything you can think of. Using these can save a lot of time in development and project cost. Not to mention, using a plugin means that someone else is responsible for updating and keeping the code current.
WordPress Themes are also great and can speed up development. Even if the final design isn't exactly what you want for your design, it might be a great starting place and can be developed far faster than a flat file site sometimes. Plus when you're ready to redesign, it's just a matter of switching out themes and styles. Your content stays in the database so it's easy to manipulate in the future.
There are more functional content management systems out there. I started off on Joomla a long time ago because I could appreciate the higher level of customization it gives you. But for most people, it's a very complex system. I shouldn't even say complex, but the learning curve is too high more most end-users to want to use it. WordPress on the other hand just works. It's a simple system and the user interface just makes sense.
WordPress is a pretty bulky system in comparison to other options. You pay for the added bells and whistles in load time it can give your server a beating if massive amounts of information is constantly being pulled from your database. A lot of sites I see on WordPress just take too long to load and this is definitely going to lose visitors. I wrote another article explaining the dangers of poor site speed that's worth checking out if you don't know how it affects you.
It doesn't really come optimized for search engines out of the box. The permalink settings are a huge help, but your meta-descriptions and titles can't be modified on a per page basis. Users are also encouraged to design their sites based on how they look using the editor. A page can easily get cluttered with h1 tags, oversized images without alt text, and poor content.
If you're building out a big application and expect large amounts of traffic, please don't use WordPress. It's great for blogs, company sites, and even online shops, but don't expect to build the next Trello or Twitter on it. There are plenty of great PHP frameworks like Laravel or Symfony that are capable of doing this and far better choices.
You're also banking that the theme was properly coded for SEO. While this isn't extremely difficult to do, some developers overlook this or make bad tag choices that put the site at a disadvantage for better search ranking.
I hate to bash on other developers, but the ones I'm referring to are self-proclaimed developers with poor coding experience. This, in my opinion is the worst part of WordPress. The CMS itself isn't too blame, but it attracts so many amateur developers that shouldn't have access to the back-end of someone's site.
There are definitely great WordPress developers out there, but discerning who they are can be nearly impossible to someone who isn't a developer. At the very least you should ask to see a theme that they've developed on their own (not purchased and installed). It's not a perfect solution and there's nothing wrong with using another theme as a starter, but if they don't have anything to provide then they probably are going to make a mess of the existing code.
And Why WordPress Isn't Actually That Bad
The claims that WordPress is bad for SEO are unwarranted. The content management system itself doesn't negatively affect your ranking in any way. Google doesn't care that your site was generated with WordPress. There are even plugins that hide every last clue of WordPress in your code. Why this rumor still exists is beyond me. The issue here is poor coding or content, but this comes down to the developer, not WordPress.
The SEO issues that do exist within WordPress can be remedied pretty easily. Grab a copy of WordPress SEO by Yoast and you can customize the meta-descriptions, titles and keywords for each individual page.
There are other alternatives to keep in mind when planning your next site, but WordPress is a great tool and in many cases it's the right choice for a client.