Beyond "hiding", GnuCash should allow user to choose (or switch) modes from basic personal finance, to SOHO, to civic group, to small nonprofit, to small retail business, to school, to political campaign, to real estate firm, to legal partnership, to medical practice, to town government, to what have you. I would start with the first five and allow others to be added as they are developed.

This does not directly add functionality, but limits the presentation of diverse features to users who need them. It also would best adapt to the vocabulary of the specific market (ie personal vs nonprofit vs business).

Wow you said it... I was just getting so annoyed seeing all those unwanted menus and windows, Fields, Settings, Reports etc with business and invoices etc

There are enough and more competitive software for business finance management one good example what I use for my business is Dolibarr...

A personal finances software is basically for home finance management. So I feel that it should be separated from ERP functionality... No harm if you have them in GnuCash but its best if its like an addon module or a totally independent software or something in similar terms.