The Q400 is probably not that bad an aircraft.
But as it is a relatively new design it will be complicated.
And it has props and pax dont like that.
The only country where it may prove its self comercially is the USA
and the regional operators there are all buying small jets.
Sales of all aircraft are not great at the moment but this machine
is not flexible enough to survive.
Same as RD mentions ATP and J41 which are no more and headaches to the manufacturer.
I hope things go well for the people at BE but I think the Q400 was not a great decision.
They were also a launch custiomer for the trojan horse RJ-X which was also not a great decision.
Manufacturing aircraft like this is a liability for the future as unsubsidised BAe discovered a long time ago.