Thank you for your input Brother Nigel. Here's my response:
There are only 9 sub-forums in the main area (Rig-Talk Discussions).
They're all necessary when you think about it, except perhaps the HCF one, which is there for legacy shits and giggles.
OTC's sub-forums are neatly tucked-away in that section, and sure, there are quite a few, but with the range of subjects possible in an OT sub-forum, it makes sense to at least provide the opportunity for some sort of delineation in order to make things easier-to-find as well as avoid the nightmare that is having only one section where the full plethora of stuff ends up. That'd be a nightmare to navigate / find threads on the subjects you're looking for.
Then there's the Manufacturers' section. Again, all sub-forums tucked-away within it and all created under "deserving" circumstances. If the owners / head/s of a company want a sub-forum there and are willing to service it, they generally get it. The fact that many of the sub-forums haven't seen any action in a while is neither here nor there. Nobody's gonna get punished for that. A new product comes out and bingo, suddenly a sub-forum is active again... but still far away from the main area.
Hopefully this makes sense to you and others who see this. IMHO the layout is logical and in no way OTT.