When people talk about historical Bitcoin returns being attractive, they are talking about an extremely short history full of incredible variance and an uncertain legal future. You can’t easily make long term predictions based on that
11 years is extremely short? As for variance, yes sure over the short term but Bitcoin has 10x’d every other traditional investment on a long-term basis. You make long-term predictions based on things like scarcity, automated inflation policy, and other anti-inflationary properties.
Based on its historical investment returns as well as its inherent properties, I would argue that at this point a zero percent allocation into Bitcoin is objectively the wrong value.