Actually, the view is not "backwards"; it's known as Occam's Razor, stated by William of Occam in 1349.
"Entia non sunt multiplicanda praeter necessititem." or "Do not multiply entities beyond necessity." This "Principle of Parsimony" can also be stated, "If two explanations equally explain the facts, the one with the fewer postulates shall be chosen".
In my first ecconomics class, the professor was very fond of saying ceteris paribus, "other things being equal". If we are going to build theories, we need to start simple with as few distinctions as possible, and then differentiate as necessary.
We must however, as general semantics teaches us, be prepared for our assumptions to be in error, including assumptions that possible differences can be ignored. These scientists began with the "ceteris paribus" assumption that things were simpler, but they were prepared enough for their assumptions to be wrong that they took the discovery in stride rather than try to force the data to fit a simpler model.