For me the key points are in this quote. I think everyone agrees it's always considerably better to try binoculars in real-life. However if you can't do that then reviews can be useful or simply interesting.
Jackjack is a reviewer, just the same as others on this site. He just happens to include a lot of pictures in his reviews which some, including me, find helpful. Some of them, eg one he did on different FOV for Swaro models, really chime with my own experiences of those binoculars.
I don't think his views should necessarily be given extra weight over others but then nor do I think they should be dismissed. As Rg548 said, it would be a sparse forum without such input.