WTF is the point of system prompts if the model just chokes and dies on it

I am so annoyed with taking time to write out a detailed system prompt with explicit instructions, then writing a regular prompt to test the model, and the model just blatantly ignores the system prompt. I could make a system prompt which includes "You should always include a brief explanation of the code, even if the user does not ask for one. The brief explanation you must include should be at least one (1) sentence long." and it response

Here's your code
{code}
Good luck!