I'm sorry, but if marketing choices were that important to your camera purchasing decision, how did you end up on Pentax in the first place? I would think the previous general lack of any PR exposure would have been more troubling than putting some fashion model in a picture with it. It's certainly not worse for Pentax's image than this:
Decide to buy the camera or not on its merits - the marketing you see above is for people who wouldn't have known about the K-30 otherwise. The K-30 is not targeted at pros. The fact that it's a great camera at a great price makes pros consider it, but the marketing materials are not targeted at serious shooters. You can't blame Pentax for wanting to target a wider audience . . . they're in the business to sell cameras.
Does it cheapen the camera? A little. Would it make me want to buy the K-30 any more than I already do? No. Does it mean that somehow the camera is less capable than it was before?