The learning curve is the thing that scares most people away from using Drupal. With Drupal Version 8, it has taken a more standardized way by teaming up with the Symfony framework. This, however, is a double-edged sword. It takes you a step further away from the typical front-end developers that had found their gem in Drupal Versions 6 and 7. By its procedural nature, they were able to build semi-complex websites without any real programming and object oriented programming knowledge. Everything below Drupal 8 was aimed at being a procedural application where you can make changes by using hooks they provide in their code (a small amount were Object Oriented, but most people would never touch this). This allows for an easy way to modify existing pages for the non-programmers who know how to write scripts a little. But these hooks are very specific to Drupal itself (hence the steep learning curve) and aren’t very intuitive if you look at PHP frameworks/applications as a whole. The documentation on how to do things as a complete novice is only subpar in both Drupal 7 & 8. By now there are plenty how-to tutorials on how to do things in Drupal 7 luckily. With Drupal 8 they decided to use Symphony2 as the base framework for the system. This allows for best practices in that framework to be used and allow the vast community of symphony2 programmers to make a switch to Drupal since it leans closer to home than the procedural approach from the previous version. Almost everything is now Object Oriented and the amount of hooks (the old procedural approach) has been pushed back to a minimum. This makes it more difficult for the previously mentioned non-programmers. They are now looking at a huge time-investment to learn OO Programming to get started in Drupal 8. I believe this is the reason why Drupal 8 is making such a slow start compared to Drupal 6 & 7. It’s a good product but they made it so much harder for the people who can write basic PHP scripts. The main area of improvement would be better/more documentation and tutorials on how to do things in Drupal 8 at this moment. It’s a leap of faith for the non-programmers out there and some of them just completely thrown off by it. This is what incites projects like https://backdropcms.org/ where they fork Drupal 7 to keep it going after it reaches EOL.
