True, plus there's the logic of pot-odds. If everyone is taking the favorite, then there's an advantage to taking the contrarian position.

It also starts making a lot of sense as a come-from-behind strategy.

There is some reasoning behind picking underdogs as they may perform better in certain surfaces or head to head against some players.

Carresan

Picking underdogs, unless you really believe in them, only really makes sense in bracket-type challenges, because then you benefit from being right for multiple rounds.