The developments in the middle east should be proof enough of the wider benefits of creating a scale hub. There must be a reason why the gulf states are pouring money into developing airlines and airports around a hub spoke model. It's possible that rather than seeing transit passengers coming through Abu Dhabi or Dubai as worthless freeloaders, the more enlightened thinkers in the Middle East released such passengers are the critical mass in a model that would allow Abu Dhabi and Dubai to be linked to far more places than would otherwise be the case. That in turn would be good for business and tourism.
If that was the plan (and I'm sure it was) then you'd say so far so good. But just because LHR has evolved over 70 years and not just the 20, doesn't mean the same principles aren't in play here in the UK