He could have at least talked with u before to tell you why he was changing the vote, maybe it was something that u did, because imo u haven't shown any lack of commitment to STEEM... Steemmonsters especially is one of the top played games on blockchains, and even people that aren't that much into STEEM or blockchain have heard about it and are playing!
Still, one single vote made u go from 21 to 1? Nice centralization of SP we got here... Let's hope another whale sees that u deserve to be in the top 20 and votes for u...
Good luck climbing back to the top 20!