Your point is well taken. That is definitely a way to explain those differences. One could definitely be in agreement with your proposition. The short answer is yes. You could very well be correct on that, and that could explain the differences.
The explanation of those differences may not necessarily lead to any additional clarity, or a lack of litigation in the court when we're dealing with statutory interpretation between two different sections. The purpose is important and the differences are important, but the plain wording is important as well.
Although your point is taken, I don't think, necessarily, the very common-sense proposition you've put forward would cure any of the problems that might arise because of the differences.