@DansLeRuSH its great that you have contributed filetype improvements. But if Cobol is so useful then Cobol users should step up and provide support for the parser.
Geany is a totally volunteer project, its is not supported by any companies. Those banks and companies you mention should be able to have their people contribute if they want support to continue (sadly I suspect they all use Eclipse).
The suggestion to abandon Cobol is because something needs to be done to continue support, and in a volunteer project, if no one contributes that, then support can not continue.
I'm not an expert on whats needed, but IIUC the problem is that the Cobol parser uses a different Regex library from the rest of Geany, and, as I asked above I'm not sure why thats an issue, and what is needed to make it work. Perhaps open a specific issue to discuss it if its an issue [pun intended].