We've had a few questions that ask "who" about something, such as who manufactures X or who distributes Y product. This is the most recent, asking who makes smart TVs.
We've also had debates about them, but I don't believe we've ever formalised them, so:
Are questions that ask about "who" on-topic?
I do not think "who" questions are appropriate. They are not for recommending hardware and can easily be changed into a hardware recommendation question. Instead, they end up asking for a list of manufacturers. An valid answer, albeit low quality, would be to provide a list of 3-4 manufacturers that meet the criteria.
However, the questions I've found that ask this type of question could be changed into a true product recommendation type question. The question being asked is "what product do you recommend that meets my requirements?" Manufacturer doesn't matter. The user is more interested in the end product.
I'm going to guess on some of the examples and answer based on those. If you have others, edit your post and I'll modify this answer.
This question is really asking for a high end, non-smart, television. They want it to have a high quality display. The question could use more details, but we can recommend a television that isn't "smart". A list of manufacturers isn't what the user really wants. They want a high end TV. Let's focus the question on that.
This question is asking for a quiet GTX960. They provide requirements for the noise range they are looking for. They provide other details about the machine. Overall, the mention of "manufacturer" in this question is really unneeded. Since the user has narrowed it to the model card they want and is focused on the sound of the fan, the questions are going to be limited to manufacturers of that model card. The question is focused on the noise level of the card. The manufacturer isn't important, but is the result of how narrow the question is already focused (which is good).
This question contains a lot of exposition about why they want a durable laptop. The user doesn't really care who manufacturers the machine, they just want it to last a decade. The true question is whether or not such a device exists.
