The reasoning behind it is that the Income Tax Act contains its own enforcement mechanisms, and imposing or requiring that for citizenship applications is really trying to enforce the Income Tax Act through the Citizenship Act, which we don't think is a good approach.
Also, we raised the issue of the potentiality that someone could, for example, think that they weren't required to file their income tax report and then would submit their citizenship application saying that they didn't think they were required to file. It later turns out that they should have and they were supposed to file. Is that a misrepresentation for the purpose of their citizenship application? Could they have their citizenship revoked for that mistake in their knowledge of the Income Tax Act? That's what the reasoning is there.