There are a few ways to look at (molasses) that is.
The main point of its use, in my opinion, is to help the beneficial organisms living within the growing medium break down more nutrients which the plant can then use.
So then, yes, if your grow has relied primarily on inorganic nutrients, and you have a rather sterile medium in comparison to someone using bat guano and kelp, then maybe molasses will provide little to no benefit.
However, if you are mainly focused on keeping a healthy bio medium throughout the grow, then yes, I feel blackstrap molasses can play a big part.
Just a couple cents to throw into the pile.