The Pareto principle (also known as the 80/20 rule, the law of the vital few and the principle of factor sparsity) states that, for many outcomes, roughly 80% of consequences come from 20% of causes
I feel like this kinda falls into the "Bitcoin is money" and OP_RETURN debate. Yes bitcoin is money and mostly transaction data but let's not throw the other 20% of use cases just because we can't envision what someone way want to do with it in the future