I used to follow recipes, against my instincts, and find them work out badly, yet the idea of the recipe is good, and on later attempts using my own good instincts, I have wonderful dishes.
So, why the difference? Maybe the measurements are not the same, maybe the ingredients are not the same, in my area...but I've learned to take ALL recipes with a grain of salt, so to speak, and adapt to suit what I KNOW is right for my kitchen.
That might be why recipes are changed. Others may have allergies to certain ingredients, or not have access to them. Does it make the recipe a completely different one, for the correction of a measurement, or the substitution of an ingredient?
I am strongly of the opinion that there are a very limited number of recipes out there, and the rest is all variation on the theme, and variation in presentation.
ViolaB