That is exactly the problem. The V6 has a very peaky torque curve. Nothing happens for quite a while, then suddenly it wakes up. But by then it is too late, and the opposition has left the station.
Most drivers prefer an immediate reaction when they depress the speeder. That makes for good drive-ability.

The hunchback torque curve of the V6 is clearly a great disadvantage and also one the 2.5V6 from Honda had. Honda increased the engine to 2.7 in order to combat it. Rover scrapped the 2 litre V6 as soon as the Turbo 1.8 hit the road, and were probably too weak by then to do anything about the 2.5.
Take a BMW or Jaguar with same displacement and compare to the Rover.
chalk and cheese!

But we can argue until we go on pension. Try it out in a comparison! I would love to see a video of V6, Diesel, 1.8t and a V8 (just for measure) accelerating side by side on an airstrip or similar. All could be automatics.

the V6 is a lovely car in many ways, but let down by an engine that is not what it could have been! It does not make it a bad car. It just is not as nice as it could have been. Rovers demise gives a hint that this seems to have been a shared feeling by many, for whatever reasons!

A pity really, but Rover, after so many years of braving the stormy seas, were let down by some notable and avoidable mistakes.