WordPress theme development is never easy. It requires a lot of patience, skill and stress. It will probably take you a lot of time and effort to start creating themes from scratch. Not to mention the security dangers and bugs that will come as WordPress updates come every now and then.
Of course, if you’re a kick-butt designer, you would have no problem about that. But still, even for an experienced developer, creating a WordPress theme from scratch is not a cake walk. And if you’re not an expert, you probably have to consider using WordPress themes frameworks.
Over its existence, WordPress theme developers have tried to make theme creation and development easier and faster. (Of course, who would want to have a difficult job, right?) Some started by creating HTML templates then recoded to PHP and WordPress codex. Of course, that’s still difficult.