Yes! It's a crucial distinction. Rationalism is about being rational / logical -- moving closer to neutrality and "truth". Whereas to rationalize something is often about masking selfish motives, making excuses, or (self-)deception -- moving away from "truth".

It's a variant of how you instantly know what a government will be like depending how much democracy they put in their name.

"If a state calls itself a commonwealth you know it sucks for the common man there" or something like it is one I've heard before.

It's at least 50% right in my experience.