"...why does being poor, make you a more credible musician?"

It doesn't. But sometimes it can seem like the route to fame is littered by dilletantes who just didn't have the songs or the chops to deliver them live. The Others and Jo Lean and the Jing Jang Jong spring immediately to mind.

There's a feeling that you can throw a shitload of money at a band, record them really well, get them bought on to big tours, expose them with well-funded, well connected PR and watch the results. None of which relies on talent. So the first hurdle any well-to-do artist will face when put in the limelight is 'Are they credible?'. Not just from critics, but from the paying public; because some might feel they've sidestepped the selection part of A&R, or perhaps there's the notion that they haven't paid their dues. Instead of honing their craft with blood, sweat and tears some coin has opened the door for them instead.

That's obviously an (irksome) class issue on the side of the listener. In the end, all that matters critically is if the music holds up. And opinions on that have been known to vary.