Lately it seems there may be some amount of concern about how questions about specific camera/lens models should be handled. (Specifically resulting in the proposal for an SE site specific to questions about camera models.) What makes a question about a specific camera model either on or off topic?
Fundamentally, it comes down to if the camera model adds anything to the question. For the most part, cameras do basically the same thing from model to model. They may have some particular strengths and weaknesses, but asking if "a particular model can handle X" is not beneficial when what you really want to know is "what does a camera need to support to be able to handle x".
The latter question can be answered the same way, however it only has to be answered once for every camera made. The answer is still just as helpful and just as easy to find, so in cases like this, the model adds nothing to the question and should be excluded.
If, however, there is actually something unique about the particular model of camera, then it would be on-topic to ask about the things that make that camera unique since they are not more generally answerable. For example, the question about Pentax K50s specific behavior for P and TAv modes is fine because it is a unique feature to that camera (or possibly can be broadened to a line of Pentax cameras).
The question one should ask when looking at adding a specific model of equipment to a question is "does the question fundamentally change because of having the model specified?" If it does, then it is appropriate, however if it is simply looking for someone to do the leg work for you rather than reading up on a) what a camera needs to be able to do to accomplish your goal and b) how to tell if a particular camera can accomplish that (such as "what makes a camera able to handle low light?") then it isn't adding anything to the site other than catering to the laziness of the asker.
I don't have an problems with questions about a specific camera model, although often, they are actually questions about many models by the same manufacturer, or all DSLRs in general, or in fact sometimes all cameras ever. Those questions are better made more general (possibly with the specific model as an answer) because it benefits nobody if we have a question about what aperture means for the Nikon D3000, D3100, D3200, D5000, D5100, D7000, Canon Rebel whatever, and etc, etc.
The problematic questions are
- "Should I buy the $MODELOFTHEMONTH?"
- "I picked three random camera models -- tell me what to buy!"
The answer to the first one is usually "Sure, if you want it", and the answer to the second one is "Yep, one of those will be fine." Sometimes a compare-and-contrast question between two very similar models can be useful, but usually it's better to just refer those to review sites, because that particular comparison is very time-limited in usefulness. In those cases, it's better to have questions weighing the relative value of specific features for specific use.
I know you didn't ask about lenses, but similar things apply. The situation is a little different because lenses generally have a longer lifespan than camera models. Here, expert review of a specific lens for a certain use can be a good Q&A. And it's generally fine to ask for comparison of similar lenses from different makers, or overlapping lenses from the same brand. But again, the problem comes in when there's shopping list of apparently-randomly-chosen zooms, and the question is really asking us to make the final decision.