Your proposed fix might have unintended side effects. It might allow people to post and re-post their question, by deleting and undeleting, or might allow spammers to post questions on multiple sites, by posting their question and then deleting it once it has fallen off the front page (which can happen in a lot less than 40 minutes on some sites).
I'm not convinced this is a problem that needs to be fixed -- at least, not if it may have undesirable side effects. We want people to study the site topics carefully before posting their question. If they ask an off-topic question, we'll still try to help them out, but I don't see a need to go out of our way to accommodate that by changing the rate limiting.
In the example you mention, the question was off-topic "because it is about public policy, not personal finance". The help center on Money.SE states that the site is for questions about personal finance, and that questions about economics and government policy are off-topic. So, if the poster had read the help center carefully, hopefully it should have been apparent that Money.SE wasn't the right place for the question. In that situation, having to wait 40 minutes seems OK. (If they want to do something constructive during that time, they could take advantage of that time window to study the help center on Economics.SE carefully and look for opportunities to further improve their question or make it more suitable there.)