Writing web content is an art form. You need to have a certain degree of talent to write engaging and effective content that will interest your audience.
However, writing web content is also skill that can be learned. And like all skills that you've learned, you can easily unlearn web content writing. You can lose your groove, your rhythm, and, eventually, your confidence.
A writer needs to write consistently, with regularity, in order to sharpen and improve his craft. If you will not make it a habit to put your thoughts into a coherent composition, then you will easily fall into the abyss of what I call, writing catatonia.
People say that writers are moody; that they need a muse or an inspiration to get the words flowing. Most writers often nurture this impression. In fact, they cultivate such idea because of a mistaken notion that inspiration is the driving force that propels the creative spirit of every artist.
Writers are artists, there is no debate about that. But you don't need a magical muse to be able to write. Writers who cling to the idea of the "inspiration" are filled with hubris. They think they are artists, ergo, they need a muse. Without a muse, they will not write. This, I call BS.
Mistaking your writing catatonia as an artistic plateau will lead you to an insurmountable abyss of unproductivity.
Sheer laziness, or more specifically, mental laziness is the main reason why writers can't write. A writer's unwillingness to think in an organized fashion will stop him from writing. His laziness to do research, to read other authors, and to form an opinion, are the things that cause writing paralysis.
Distraction is also a big obstacle that all writers must overcome. They might be preoccupied with other things, they could be distracted by mundane everyday chores, they could be suffering from depression, or maybe, suffering from social network addiction. In worst cases, they could succumb to porn-surfing.
Whatever the reason is, you can not blame lack of "inspiration" for your unproductivity. That is because the world is full of inspiring things. The smallest things in our everyday lives could be used as sources of inspiration. All you need to do is to write these things down. Form words, sentences, and paragraphs. And give meaning to the things and events that surround you.