Because that is good advice for want of a better workaround. You act like that is a huge burden, it's typically very easy to do! Searching for a model number and 'manual' will get you to a manual, most manuals are very short and quick to parse especially if all you are looking for is 'will this require an app' or similar.

So, yeah, it is good advice if the outcome is important to you and you dont know a better way to protect yourself from accidentally buying something like that. Unless you know a better way and are holding out on everyone?