The issue of Chametz is one area in particular where many feel the need to be stringent
That’s fine, but kitniyot is not chametz, and in many cases, does not resemble chometz, and in many cases can’t be ground up and made into bread. Tell me how green beans and peas can be ground up and used.
And as long as we’re trying to come up with explinations, someone tell me why peanut oil was fine when I was a youngster, but can’t be used now? (We ate peanuts on Pesach growing up; I eat them now on Pesach as well. If they weren’t kitniyot then, they didn’t suddenly and magically change status.)