Although i'm not well versed in multiplayer, i've seen two types of players: those who play for fun (you guys rock), and those who play to win (you guys don't rock as much because it's boring to play that way). Shovellers tend to be the latter, since it's not exactly the most exciting move there is. This is much to the detriment of the former, since the latter USUALLY don't mind using boring but effective moves.
Although i am a sore loser, i don't mind losing in a spectacular manner, but this won't happen if the opponent is afraid of going balls out because they might lose to a crazy accident.
Point is, shovelling is effective, but boring (particularly for the other player), since you basically rob the fun from them by making them unable to fight back properly (if they don't manage to predict the fuggin future). If you're cool with doing such a horrible thing, then get ready for flames, because people WILL be butthurt over it.