T20s may not entirely be decided by luck, but certainly there is little scope for tactics and recovery. Any game you shorten the format you increase the chance of the weaker side winning, there'd be many a shock in football if games were stopped at half-time or in golf if played over one round or in tennis if decided in one set.
What the ICC needs to do is ensure TV and board greed don't conspire to produce too much cricket so all three formats can live side by side in disharmony. The ideal way would be to have fixed tour formats of say three Tests, four ODIs and two T20Is which would give you 21 days of cricket which, with appropriate amounts of warm up matches should mean they are do-able in 10-12 weeks.