An article that concludes "the benefits of standing desks may be overstated" isn't really the same thing as "standing desks [are] not really good for you."

Personally I can say that I've enjoyed the transition. My posture has improved greatly. I have a lot less back/shoulder tension and pain. I find myself naturally more inclined to take breaks and walk around, which has many benefits of itself. It took some getting used to but I often spend ~6 hours a day standing instead of sitting.

If you're going to conclude that standing desks are "just a fad" I would hope that you have better evidence than that.