That’s a good point, but not all that good.
You’re getting into Law Theory, more specifically when things that shouldn’t happen, according to legislation (in this case, the Code of Conduct), happen so often that it just becomes the new normal. It doesn’t mean that people like doing it, but sometimes they have to do it in order to not get into a disadvantage. In such situations, the infractions are way to many for the police forces to properly deal with them, or even the backlash from the populace would just be too much trouble of it’s worth.
In the case of Pro League, other tournaments or even any multiplayer game, people can choose not to do it, but there’s nothing really enforcing it, so they have to do it not to be in a disadvantage. And there are soooooo many people should be punished. Beyond that, probably it’s less effort to just fix these problems than it is to track and punish everyone. It’s an easy choice, for Relic, and absolutely normal in these types of situations, where the harm done is not that big if, in the end, both sides have acess to doing the same thing, and end up doing it. That’s why, after all, not even the Tournament rules prohibit said behaviors.
And “abusing broken units” it’s not an exploit. Even if there’s something wrong with their programming, the unit is there, and the user could claim a UI problem (like horse archers with different attack speed, or demos with ludicrous range). It can be, according to some people, “morally wrong”, due to the game being less fun or something like that, but you can’t punish this type of stuff, at all.
The game is already suffering with some backlashes, and punishing people for what you pointed out would, most likely, reduce even further the interest of a lot of players that are pro and/or stream a lot. Imagine the size of the fire that Relic’s PR would have to put down, probably to never actually revert said critical error.