Friends who worked at Woodford and Chadderton said things started to go down hill when the BAe suits took over. The 748 was designed by people involved in or trained by the designers of the Lancaster, Lincoln and Vulcan. The ATP was designed by a different generation using computers.
The various changes and the final rebranding of the type as a Jetstream were sticking plasters applied by a management determined to eliminate anything that carried passengers from their inventory.
The final BAe stupidity as far as the old AVRO operation was concerned was the axing of the RJX. Now I'm not going to say it would have been a world beater but it was axed in the immediate aftermath of 9/11 on the basis that the market had evaporated in the flames of the WTC. Many of the RJX team went to Canada, the US and even Brazil and, apart from the loss of talent to the UK, Bombardier and Embraer not only proved the market was still there but managed to grow it and became leaders in the regional jet market from a very small base.