If you haven't used it how much sense does it make to criticize it? "I do not like Green Eggs and Ham..."
Years ago, before the web made finding info easy, someone recommended Superthrive to me. I used it on & off for a while. Unlike the proponents, I could discern neither a benefit nor an issue with its use. After getting a bottle & pouring over the label, I did (& do) get the creeping feeling that I was taken in by a swindler just by purchasing the stuff.
The label & its claims seem to be designed for that effect - - ie: "#1 Perfecter"
Many people swear by Trichoderma where as I had a bad experience with the stuff. You don't hear me calling it snake oil or the trash can is the best place for it (even though that's where it ended up). Nor do you hear me recommending it. Try it first with an open mind, not expecting miracles or disasters, and then form an opinion. If it works for you, use it. If it doesn't, move on.
On Trichoderma, there have been a number of controlled studies (performed by reputable institutions) that show a clear, measurable & statistically significant benefit. Maybe I'm not looking in the right places, but I've yet to find a preponderance of studies (or any) by reputable institutions (or any) that have shown the benefits of Superthrive. Again - maybe I'm not looking in the right place. **
As far as using the stuff, I
actually don't have strong opinions either way. I didn't set up any kind of real study to try & test it but I also didn't have any positive observations that caught my attention. As I mentioned above, the label itself makes me feel I've purchased & used snake oil. In general, I think S/T fills the need for CP growers to 'do something'. Typically, we learn quickly when we start growing CPs that classic fertilization is deleterious. Using 'normal' houseplant media is bad. Heck, we even have to let our temperate CPs go to sleep for several months every year to keep them healthy. Using S/T allows growers to feel like they're actually doing something for their plants (a form of grower's placebo). Imho.
** - to be brutally honest, I'm not really looking at all. When I toss out a bit of sarcasm about S/T (as I did in my 1st post), I know the proponents will throw any valid studies in my face, if they exist. If they don't exist, there will be a few arrows in my direction and then 'crickets' as far as proof goes...