I got this letter today from someone trying to figure out whether Drupal is a good place to start. I thought it might be good to share the question and also my answer so anyone who's interested can also contribute some thoughts:
Great questions. They're hard to answer objectively, since I've been involved with Drupal for a while and of course I want everyone to use Drupal and participate in the community now. But, which I shifted from doing general PHP development for clients to doing Drupal, I did so for a couple reasons. The first was that I believed it would speed up the process of developing sites and provide a standard that other developers could plug into, either as part of a team with me, or as someone taking over the project later. In general, I think I made a good decision in that respect. I was able to take some ideas that I'd developed in my work on a custom CMS and contribute these as modules, and that also helped me get started in the community and get the ideas out there, which felt good.
The second reason I chose Drupal was because of the community. I was able to connect with a couple people locally and we started a local meetup, and I started participating online in a variety of ways. I also went to a few Drupal camps which was a great investment in terms of the people I was able to connect with. Since then, I've known people from several different software communities, and they all say that Drupal has a fantastic community. It has mature leadership, great events, and a way of contributing and sharing that other communities aspire to.
Drupal also has some great momentum. The people I know who know a bit of Drupal get picked up quick by companies who do Drupal work or use Drupal in-house. There's still more people that want to use Drupal than there is talent to implement all the projects that could be done. Of course, you never know where things are going to go in the next 5-10 years, but there really is a ton of growth in the area.
For me, moving to Drupal was great. It got me out of the bubble I'd been in by being a solo freelancer with their own custom CMS, and it got me into a community of people that I still really enjoy.
One thing I hear from the outside is how PHP maybe isn't the best technology to centralize on, which is a tricky one. Real developers tend to wish that PHP would fade out and be replaced by something more fun and efficient. But, I've never been a real developer, and have been able to get what I need done done within the confines of PHP, and Drupal has helped accelerate most projects.
I hope that helps. I'm going to go ahead and post this in an anonymous way so you can get some other feedback, though, as well.