Yes, some muddled jumping to conclusions has been going on in this thread:
ATP was hardly BAe Manchester's "attempt to enter the turboprop market" as it was developed from the 748 (RR Dart engines, for those that need to be told).of which they sold nearly 400.
Fokker did a similar "upgrade" to make the Fokker 50 from the F27.
The commercial success of airliners is hard to judge as an outsider, but on the basis of 387 built if the 146/RJ wasn't commercially successful I'd be surprised. More Viscounts were built, but again who am I to say if it was a commercial success?