The main idea about the sections is to give the members oppotunity to have their small forums (sections). Besides, it helps to keep good developers/coders inside the forum because in this case they have their own place/home. And they may create commercial things inside the section because it is their own small forums. What is next? Next is private groups.
So, it is how our forum is developing.
The forum is developed by members and every admin want to keep good developers/coders inside the forum so we need to section.

Sometimes we need a sections to separate some subject from the whole forum because this subject is too specific. For example, we are having Harmonic trading section, Digital Filters section and News/Signal Trading section.

I agree: we should have one section for martingale/grid/hedging/arbitrage systems and EAs and in this case everything related to this subject will be in separated section and the whole forum will be ready for new developers/coders/members to come and to start new development.

Yes, I agree with el cid: we should have one section for oil, gold, commodities, indexes and so on.

Section is just ... we are sorting everything posted randomly on the forum and moving to separated place.