Organic growth means growth of your business through means other than takeover and acquisition. Therefore Easyjet has grown, however modest you may deem it, in an organic manner. I just think that it is important to set out what 'organic' actually means from a business perspective.
Easyjet's strategy is clearly working. However much bases are growing or reducing the financial performance of the business is ultimately being championed by the city. It's profits targets are not only being consistently met but exceeded and despite a dip experienced by most carriers, it's share price is still exceptionally strong.
Easyjet is a European carrier and as such Europe is it's home market, like Ryanair it follows the best returns. Remember also that there was a time where Ryanair saw reductions in its 'home market'.
With a sustainable fleet plan, a robust performance and a reasonably good reputation Easyjet are proving that throwing assets the length and breadth of Europe at an exponential rate isn't necessarily the correct thing to do.