My opinion is that if a player plays a game to try and lose than that is wrong, wrong and unsportsmanlike.

Trying to win every game played, regardless of the quality of the opposition, is right.

Giving up just cause a player lost a few games is wrong.

Battling to improve and change the fortunes of a team if they are doing badly is right.

Having the power to pick and chose which matches to try and lose and which matches to try and win is again unsportsmanlike and manipulates the league position of other players, all of which is wrong.

Accepting you might not be the best team and you might not win this time round, but still giving everything you got to finish as high as possible is right.

All the above is in my opinion.

Is tanking cheating .. nope .. it's allowed in this game.

Is tanking a good way to play the game .. of course not .. intentionally trying to lose games is just wrong (imo)