By ceasing to operate the Dublin Gatwick route Aer Lingus have created a monopoly on this route for Ryanair. Monopolies are not in the customer interest.
Why is this important?
Thousands of us find Gatwick a convenient and easy airport and do not wish to fly Ryanair. By removing the Gatwick option, not only is a Ryanair monopoly created, but it forces those of us who will not use Ryanair, to have a far longer and inconvenient journey to an alternative airport, and in doing so, creating a negative environmental impact.