The build quality is fine on the interior, the design of it is somewhat agricultural though and its what put me off it, its not bad quality, its design and material choices you are referring too.
All cars have issues at some point. Its just some are more prevalent than others. Ive owned multiple Audi's, VW's, Subaru's, Mitsubishis, and my CX60's have had more problems in six months than ALL of those put together. So build quality is definitely poorer on the Mazda, as seen by the fact they have to line the doors with rubber to make they stop sounding like a tin can, and the suspension starts to squeak after a few thousand miles - this is build quality not pleasantries.
Reliability and build quality is also different. I know the Mazda will fire up every day come rain and shine and its reliability is A1, but the build quality is still poor.