I wouldn't go so far as to say anyone is cheating necessarily, but playing the robot to gain position does violate the spirit of the game.
And it's much worse than you think (and here is why you need nerds around
Of the current top 12 players only 2 have not played the robot at all. Leaving 10 of the top 12 who have played the robot. Of those 10 only 2 have played any real players in their last 50 games. Those two have played the robot 46 of 50 and 31 of 50, respectively. That means that in the last 50 games for each player in the top 12 who have played the robot at all, overall they have played the robot 467 out of 500 games. It's obvious that most of the top 20 are only playing the robot to maintain their position in the top 20.
So, I propose that players cannot gain elo from playing the robot. Also, players cannot add to number of games played or victories by playing the robot.
Finally, I propose that the current rankings are contaminated with robot elo gain so all previous robot elo should be eliminated. My proof for this contamination:
(these are not in order) In the top 15 in ranking, these players have played the robot:
Played robot 160 out of 180 total games
Played robot 160 out of 161 total games
Played robot 318 out of 545 total games
Played robot 225 out of 256 total games
Played robot 212 out of 311 total games
Played robot 486 out of 596 total games
Played robot 117 out of 130 total games
Played robot 177 out of 228 total games
Played robot 150 out of 169 total games
Played robot 1884 out of 2743 total games
That's 10 of the top 15 in ranking. Two others have played to robot exclusively if their last 50 games.
Conclusion: Players are using the robot to artificially boost their ranking and gaining top spots and staying there.