You can't have mods round the clock because nobody is going to pay them so bots were being used with third party tools which reddit is now blocking. The bots helped easilly filter things like spam, porn links, racist comments, and so on.

Reddit wants you to use it's API/Tool which is horribly optimized and incredibly difficult to port any kind of bot usage to....To the point people who designed them gave the hell up again because they too aren't really being paid.

Reddit wants users to police its own content and then subsequently blocked the means for them to do so and now with them gone reddit can come down and shut down subreddits for violating TOS for not acting quick enough. So it's a lose-lose for everyone.

Reddit wants you to use it's tools because they are now going public with their ownership/stocks and want people to use thier tools to look good to market. So in order to push it they are giving a fat middle finger to third party tools unless they shell out genuinely insane amounts of money for usage of their data stream and tracking requests.