> I don't get why people hate it.

Because it is hard to manage the configuration. It's why tools like terraform exist.

Anecdote. I worked for a small company that was later acquired. It turned out one of the long time employees had set up the company's AWS account using his own Amazon account. Bad on it's own. We built out the infra in AWS. A lot of it was "click-ops". There was no configuration management. Not even CloudFormation (which is not all that great in my opinion). Acquiring company realizes mistake after the fact. Asks employee to turn over account. Employee declines. Acquiring company bites the bullet and shells out a five figure sum to employee to "buy" his account. Could have been avoided with some form of config management.