Maybe it's different now but a few years back scalers in some BD players were actually better than some other options. I mean PS3 upscaling was good.
Really depends on the chip involved.
Now it doesn't matter so much but there are probably still cheap chips being used in some things that don't do a good job. My old BD player has decent upscaling so I've never had any bad experiences so far
Never used any game consoles for playing DVD or BD myself though, always thought it was wasteful using them for things other than games but that's just me.