I would expect the following kind of writers to use that that disclaimer:
* The writer expresses poorly considered opinions, loosely holds them. They won't bother defending them.
* The writer expresses anodyne opinions that might one day become controversial, they won't bother holding onto them when the rest of society moves on from them.
In both cases, I wouldn't bother reading what they had to say. I could open the opinion section of any newspaper to get the same content with twice the conviction.
Nothing wrong with hedging your opinions in-text. But if you're hedging everything you say before you've even bothered to say it, you either have nothing interesting to say or probably censor yourself enough already.