Can anyone shed light on why the tune changed from the original to Life Is Like A Mountain Railroad? Was it likely someone didn't know the original so just winged it? Wung it? Wanged?

I do like the LILAMR version better, but is it a musical 'sin' to do that version? And yes, I know I can do it ant way I like, but I am curious as to proprieties and sensibilities on occasion.