I think that's being a bit unkind, it's simply clear that the people are not experienced with computer vision and/or image processing in general. They approached the problem from their domain and found the solution that worked for them. If I had gotten to the point that I wanted to do a domain-specific image segmentation heuristic I would certainly build it up from a series of filters and image morphology steps. If the performance (both accuracy and speed) was satisfactory, I don't know why you would invest in optimization at that point. Also, from experience I know that implementing algorithms from papers is a slow and many times painful process as the original authors generally don't publish reference code, and if they do it's probably in Matlab. And if they don't have someone adept at image processing their potential for success would likely be low.

Also, OpenCV includes functions for image segmentation. If they couldn't use that, it would have been nice for the article to at least touch on why.

I agree that a quick "Here's what we tried that's readily available" would have been good for others to learn from, because for many the general solutions would be sufficient.