Geez...there's some funny thinking going on here and it starts when people don't know the difference between a 717 branded QLink and a Dash 8 with the same branding. Its also not helped when people don't know that Qantas operates mainline, Jetstar and QLink into Hobart. Quite a mix.
They tried dropping mainline services and replacing with Jetstar and copped a pasting from business pax for their troubles so the 737 service was brought back at business travel times. They have introduced a Dash 8 service as well but not proving popular with the punters. Something about propellers and travel times I understand.
Now a 737 can't be supported by pax numbers to and from Tassie outside of peak travel times so why not replace the Dash 8 with a proven airframe for less than optimal pax numbers. There is a contractor with the right airframe and there are a limited number of extra airframes going cheap. Job jobbed, or hopefully so.