That's a lesson I never quite seem to learn. And I'm finding out that I don't much care.
I started reading a book. It was a free download and, such is my experience, my expectations were lowered. I have, to my regret, learned that there are far more dreadful indie authors than there are excellent ones. Anyway ... the the book's premise was interesting, but the execution awful. I never made it past the second paragraph. What little I did read was riddled with grammatical and sentence construction errors further bogged down by a boring info-dump.
So I left a negative review warning other readers of the pitfalls of that book. And, yes, I did state in the review that I did not finish the book and why. It's important to state why.
I look at writing as a craft, much like cooking. It's a skill that requires practice and learning. Just as you would expect a chef to know better than to pair popcorn and grapefruit with Merlot and call it fine dining, I expect an author to understand the rules of composition and to use them with competence. That means knowing when and where to capitalize words and use apostrophes and commas.
It's been said that my expectations are too high. I think general expectations are not high enough. You wouldn't patronize a restaurant with a chef who can't cook; why patronize an author who can't write? Just because you have a good idea doesn't mean you have the skill to carry it out. Writing is hard word, it's skilled work. If you aren't skilled, your audience will know and lambaste you for daring to promote yourself as such. And so they should.
Arrogance has no place here. Grow a thick skin, take your lumps, learn from the criticisms of others, and develop your craft.