Most CPAs literally do not know anything about cryptocurrency. They have no idea what they are doing in this space. You're talking about dealing with people who are still at the level of "the internet is a series of tubes".
WoW Gold is just as income producing as Steem Power is. There are thousands of companies generating MMO gold and selling it. It is immediately fungible, much more so than Steem Power. There's no meaningful distinction here.
In fact, the argument for taxing all WoW gold is even stronger than for taxing Steem. Just like the IRS thinks it deserves to tax you on $100 if you find a $100 bill.