Because this isn't twitter, there is no character/word limit so I consider taking a little extra room to help the reader understand where I'm coming from to be a good use of available comms bandwidth.
> > It is not about conviction, it is about accurately displaying the source and potential veracity of the information being presented. > Why? This isn't an academic discussion.
Because I prefer to be accurately understood in non-academic contexts too.
> If it looks like you're presenting something as a fact and I think you're full of shit...
My point is that if it looks like I'm presenting something as fact when that was not my intention then I have failed to communicate properly, and you unnecessarily think I'm full of shit.
> It's incredibly tedious to read
Here you make the case for me. This could just be your opinion/feeling which is fine, or it could be you stating that your opinion is the only correct one and everyone finds it tedious (or should). In the same way a little extra wordage can avoid me looking to be full of shit, a little extra in the sentence fragment would reduce the chance of you coming off as someone who is overly self-important and assumes his thoughts are universal facts. Maybe worrying about how I sound in this way is a neurotic issue...
> How reliable is your source?
So to avoid problems with the reliability of my source, I should just not let anyone know what the source is? Basically "trust me, I'm from the Internet, we know these things"?
> If you link a study that says "vaccines are bad" but there are 300 other studies that say "vaccines are good", are you really being objective?
EXACTLY. I don;t see how pointing the that one study is worse than just stating the fact/opinion. With the link the reader can nip off and see if it looks like what they would consider an acceptable source. With just that one link and no others a semi-educated reader can make a judgement as to whether my opinion is well enough informed to be trusted in any way. Heck, on a good forum if you were to post a fact/opinion based on a single source (and state the source) helpful people might suggest other sources you'd like to review, and this extra information could be useful to other readers too. Of course such discussions can get a bit flamey, but that is a human failing for another discussion!
> If I say "the barn is red", do you want spectroscopy results?
Not quite. You also need to provide the results of a scan of the back of your eye, we need to know what signals your brain gets from the eye in response to the wavelengths we consider to represent red - your optical nerve might be wired up wrong. Of course these things can be taken too far, but I don't consider making it clear that something is opinion (or believed to be a fact but one based on limited research) rather than something I consider an absolute incontrovertible truth not to be too far.
Yes, the reader needs to take some responsibility for not jumping to conclusions based on the exact words we write, but the writer either needs to make a little effort to not be misunderstood or accept that some will completely misjudge where they are coming from (and of those two options I generally choose the first, you presumably prefer the latter approach).