Text-based reviews have advantages in comparison to video reviews, which mainly relate to content and costs (in terms of time).
First, to present as much valuable information as Gordon does in a video review would make for a 2-hour documentary, which nobody is going to watch. Instead, one might make a 5 or 10 minute video, which would not present nearly as much information. Furthermore, compression of the video in editing software and by a site like YouTube means that image samples, or crops thereof, will not represent the true quality of the images. This is what many people look for in reviews, and why they prefer text-based pieces.
Costs differ significantly too. Writing a long review takes a lot of time, of course, but if you've ever had to create a 10 minute video (with jump-cuts, titles, etc., as well as compressing, uploading and the like), you'll know that it takes much much longer to create a video than to simply write a piece of text. The more time you spend creating a single review, the less reviews you can write, which ultimately results in you making less money.
Video reviews are a good means of orientation if you are not sure of what camera to buy. Then, once you've decided on a model, or are torn between 2 or 3 models, you can read text-based reviews to get all the details and make a properly informed decision.
If you want to watch more videos while narrowing down your camera selection, head over to YouTube and search for whichever model you are interested in. Be careful with channels like DigitalRev TV though: they might be fun to watch (I think so anyway), but the information they give you is quite basic. To be sure that you get the camera that is right for you, you should probably consult a thorough review.