Every camera manufacturer has their issues. Pentax is no different. Nothing is made like it used to be. They want things to fail so you'll keep on buying. Look at how cheap DVD and VHS players have gotten. They're so crappy one seldom lasts a couple of years without issues. The buttons and batter on every MP3 player I've owned have gone within a year or so and they all have proprietary rechargeable batteries now that most of the companies that make them won't replace. I really think that's intentional.
They talk about limited lifespan like things are supposed to break overnight now. You're lucky if you get a year's warranty on anything anymore. They all want to sell you maintenance agreements that go to 3 years but just try actually getting them to replace something if it does actually break in that time. Been there done that, been furious when it didn't happen. I don't buy long term agreements on electronics anymore simply because they're a total waste of money. It's a complete racket and even when they do honor them quality control in the repair places is iffy. I once got the same HP computer back 3 times and it was never fixed though they had it for 18 weeks almost. That's why I don't buy HP computers anymore, even when they're practically giving away things like the touch pads.
Pentax's QC has had its issues but I hear people talking the same way about the repair shops for Canon and Nikon and such too. What you have to remember is they all get their parts from the same places. QC issues affecting the parts affect them. With all the bad things going on, quakes, flooding et all it's been a bad time recently for the places where they make a lot of the stuff camera makers use. I would expect we'll see a lot of defective electronics in the near future actually and a lot of shortages too. Not just for Pentax but for all the camera makers, the car makers, anything that gets made over there.
Overall I think Pentax is a pretty good brand. They may not have the best support on the planet sometimes but I think they do all right for the most part. I have no hesitation in recommending them. I love my little K-x actually. Even if I suddenly got rich and could afford a K-5 I think I'd still keep it. It's an awesome little camera.