There is a growing sentiment that WordPress - though incredibly well supported and ubiquitous - is simply far too complex for some projects and for some customers.
Obviously, I think so too. That's why my company is building Barley.
Here are a few other notable people that seem to believe the same thing, that while WordPress is a powerful tool and it is providing their livelihood currently, it is time for more simple solutions. More choices.
In my case, I’ve become increasingly passionate about creating minimalist/simple website solutions for which WordPress isn’t quite suitable as a platform in its current state and direction. As WordPress continues to change, the passion I once had for my WordPress theme business continues to become more of a chore than anything else.
The WordPress motto is "decisions, not options" - and yet there are still too many options, too many settings, too many things which you have an unnecessary level of control over in the administrative user interface. Things like admin colour schemes, quickpress, press this, post-via-email, remote publishing, inline theme editing, media editing and multi-everything. Things that many people have never even used.
There are a lot of web sites. Billions, perhaps. And each of those sites have different needs. Some sites are blogs, others are small business web sites, others are photo galleries, others are one pagers of information, and some are pages that let you buy things. There shouldn't just be one tool to build all of these.
There also isn't one, single, clearcut answer to "What should I use besides WordPress?" because, in reality, you should choose a tool that works best for the project-at-hand. For some web sites WordPress is the clear and obvious choice. For others, such as small business sites, event sites, professional profiles, and others - perhaps Barley is a good choice. And for those of you that prefer to write in Markdown perhaps Ghost or Dropplets might be fun to use.
As a web developer you should have a few different tools in your bag so that when you need to reach for one you grab the right one for the job.