I think it's part of the battle as an anon. They make it more difficult for new accounts these days, and will only let you post once to /r/politics every 15-20 minutes or so.

Why am I being told "You're doing that too much..."

Karma is stored (internally) on a per-subreddit basis; if you are new to a subreddit, you'll have to be patient. The delay will decrease as your karma in that subreddit increases and it only takes a fairly small amount of positive karma before the timer will turn off. This applies to both posts and comments. You can also get the timer turned back on if you make a lot of negatively voted posts/comments.

Pretty easy to post some lies and get upvoted to prime an account if that's the goal, but that's not my style.