As with most things in life, I think that this question is more than black-and-white. While I usually do not react well to answers that only need a quick browse through the manual, I do not vote them down usually and try to be as polite and helpful as possible, while sometimes mentioning that reading the manual is what pros do. ;-)
Some things I experienced and what I think of them:
Things that require experience, not a manual:
E.g. Asking about an EOS 7D Mark II's AI Servo (a.k.a. continuous AF) modes and when to best use them..
A professional sports photographer might know the AI Servo modes by heart - yet I, as someone who does not shoot in AI Servo more than once a year, am absolutely clueless if the modes are a feature - or just a marketing gimmick.
I would consider this a good question, as it is about something that is hard to find out about. Candidate for +1.
The manual is badly written:
This is what I call "the Sony problem": While I love both Nikon's and Canon's manuals, I do not understand the layout of Sony's manuals at all. I really tried to understand the a6000, but gave up after around 30 minutes and went the "ask about everything that you cannot find out in 10 minutes by clicking around"-approach.
Manuals might be badly written in different languages and/or for different devices, and they might miss certain things (
e.g. How to delete a memorized AF point with an EOS 5D Mark III) or feature them at a spot you will not expect them. They might have wrongly translated names for features - or the feature was named badly by the manufacturer in the first place.
If that happens, it would be nice if the OP would say so, e.g.
In the Hungarian manual p. 17, <XYZ> is explained. However, when I try it as explained there, it does not work. I do not understand the English manual, either. Could someone please point me in the right direction?
No problem here - at least with more difficult settings.
Things people consider broken:
E.g. "My 5D III's LCD does not darken when using viewfinder and it stopped providing information, too"
The typical workflow for bad things to happen is:
- Restart the device
- Try different settings for error reproduction (e.g. does it only affect a certain lens? Is the camera misbehaving only in manual modes?)
- Consult the manual and the internet: Has the error occurred with someone else before?
- Reset the device
- Freak out and/or ask at photo.stackexchange.com
- If point above did not help: bring your device to a professional repair center and/or buy a new one.
I had such a moment when, for some reason, I forgot that the Auto ISO of the 5D III defaults to 400 with a speedlight attached. 10 minutes later, I knew that I simply suffered from very early dementia.
No opinion here - I do not like these questions, yet I myself asked some of them. Should not happen, but most certainly does. Errare humanum est.
Lack of knowledge that leads to not knowing where to start looking:
E.g. "Can't control shutter speed/aperture values in P mode, half clicking the shutter" and also the question that spawned this meta-question.
There is no reason to not have a quick glance at the manual. At this level, even the quick start guide might provide substantial knowledge. It may not be necessary to learn every page of a manual by heart to ask a question here, but it definitely would not hurt to look at it for a few minutes. After all, if you have to ask about every dial, mode, and setting, those will fill up several pages, and while asking
What does the top dial do? might be quicker than looking the stuff up in the manual, waiting for someone to write an answer (and then reading/understanding that) certainly will not save any time.
To me, these are sort-of-bad questions. I would try to answer them, yet point out that the manual is a must-read for anyone that wants to comprehend all features of a camera.
Under special circumstances, I would consider these as bad questions: If I just need to look at the schematic drawing of the DSLR in the manual (usually around p. 3) to find out where to read about it, it is the only definite candidate for a -1 to me.