You'll find equally as many if not more remain reasonably faithful to their original core function. Banking? Petrochemicals? BA may be a business, but it's business is air transport. What feasible switch of core function do you see BA able to undertake? Finance? Not with the state of ours. Aircraft leasing? Beaten to it by GECAP and ILFC. Marketing? Were good at it but it won't generate anything like enough profit. Travel agent? Insufficient profit once again. Virtual airline? Ayling experimented with it and Rods been rolling it back ever since.
Whilst a fundamental core function switch is hypothetically possible, the fact remains that BA has such vast investment in airframes, infrastructure, operations and personnel that any significant switch in the next 20 years is little more than a pipedream. The board is beginning to make noises about long haul fleet replacement. That does not sound to me like the planning of people who want to get out of the air transport business.