It's not easy to admit, even to oneself, but many indie authors experience feelings of resentment...toward each other.
This Market Ain't Big Enough for the Both of Us
It's really not difficult to see how this might happen. Wouldn't it be a whole lot easier to sell books if there weren't so many books? Wouldn't it be easier to market if there wasn't so many other indie authors marketing? Wouldn't it be nicer if they would just go away?
And when you find other indie authors who publish books that get bad reviews and get a reputation for being error-riddled...well, it's sort of easy to start having feelings of resentment. I've resented other authors in the past, and my meanness isn't even limited to indies. I have a practically lifelong obsession with disliking Stephen King, for reasons we don't even have time to get into.
It's completely normal to feel dislike, even some hatred, for the competition. What you have to realize is that other authors, in all forms, are not your competition. They're your colleagues.
Scratch That, We Can Work This Out
Readers read, and writers write. It's an endless cycle, and it means there are plenty of readers to go around. People who read books don't read just one book, they read many. Some readers read several books a week, to the tune of hundreds of books a year. There are always going to be enough readers no matter how many self-published books are out there. Though, naturally, the scales will balance. Well-promoted and well-written books will sell more copies than those that are not promoted and poorly written.
It's natural to resent other books that seem to be taking readers away, but you have to remind yourself that this isn't the case. Other indie authors can help you take your career further, in fact, because there's a strong sense of community and supportiveness among those who self-publish. Use the indie community, instead of resenting it, and you'll find that you can gain a lot from your fellow authors.