I think that's a bit unfair! The white-tailed eagle is a red-listed species and in my view just as deserving of dedicated conservation action as all of the other red-listed bird species in the UK - skylarks, tree sparrows, bitterns etc.
We're fortunate that most of our red-listed species can be conserved 'in situ' through conventional methods such as habitat management, increasing natural food supplies, nest site protection etc. However for large raptors, such as WTE, the only feasible way of increasing the population in a relatively short period of time is by a re-introduction. I'm sure WTE would recolonise under their own steam eventually but it would take decades.
I don't for one minute believe that tourism is the main driver for the project - if it was, why choose coastal East Anglia which has more than its fair share of tourists!