(I love it when people with no experience say that about experts who make their living from doing whatever it is. There's something v satisfying about it, especially when they're proved wrong later. Schadenfreude in action. But back to the post...)
Even I, with my tiny TV screen, could see that the standard of work was poor and said as much to a friend I know who is busily doing up a house. 'Ah,' he said. 'It's all about the preparation. If you skip on that, you'll always end up with a poor finish.'
I don't think the analogy entirely works with writing because while some writers plan extensively before they get started, others head off into the blue. What I do think is that at some point a lot of work is going to have to be spent on doing stuff that doesn't always seem obvious.
That may be planning, it may be research, it may be editing, it may be character development, it may be re-writing, it may even just be thinking. Whatever, actually doing the writing is a relatively small proportion of the time that should be spent on a piece of work to produce something that is easily readable.
In my experience, both personal and that of students I've observed, there comes a 'Clunk' moment. Oh, your brain clunks. It takes a long long long time to write something good. It's not something that can be bashed out by next Tuesday. Craft skills have to be learned, through classes or practice or both. Time spent is key to getting a good finish.
And if you don't believe me, if you think I don't know what I'm talking about, well....you can guess what I think about you!