Also I don't see why the GDP of the Bitcoin economy can't be estimated, just as the GDP of many small countries are. In fact it should be easier, since the blockchain is public, whereas national accounting statistics miss out on a lot of stuff.
Of course,
it has been. The problem is that much like the "power rangers" that like to write (bad, useless, buggy) code but don't like to read, just so the "economy experts" on the forum love to write (bad, useless, ignorant) nonsense but don't like to read.
Generally speaking it's the dirtiest that hate showering most and the ones that'd have the most to gain by reading that avoid it the most.