Nothing wrong with it, tbh. Many of the 'innovations' we've seen (carbon handles/backs, hexagonal cutouts, Woodworm's concave edges, etc.) are snake oil. It's all still wood, just bats are weighted/balanced more scientifically these days and I don't think there should be restrictions on something like shaping your bat differently.
Plus, I don't think it can be over-stated that techniques have changed, the greater focus on getting into position and having multiple hitting options vs having one specific shot for specific types of balls means guy have more quick-scoring options. Just have to watch footage from before the early 90's to see how technique has evolved from 'if it's short play back, if full play forward'.
Mind you, it's also meant they have many more ways of getting them out as blokes coming up against Test fields and green decks are finding out (Phil Hughes and Steve Smith, looking in your direction)..... I'd be surprised if blokes in the past 5 years are scoring as many Test runs as those in the early 00's.