Most people who have had small dealings with cryptocurrencies wouldn't really care much about checking that box. Heck, it could be that even large traders would ignore that and check 'No' in the end and the IRS wouldn't know, unless they are already watching some people who are getting some big gains on cryptocurrencies. They are slowly moving the checkbox up for better visibility, and it's kind of a passive-aggressive move to them since as of late, a lot of traders are raking in profits due to the sudden boom of cryptocurrencies in the market.

They really want to establish the fact that they are serious in taxing cryptos, and they might add some more questions in the future if they think that that checkbox wouldn't suffice on what they wanted to do.