@Tagron
Sorry that does seem quite bad wording. I'm basically saying that EasyJet and Aer Lingus have been the only two carriers so far to successfully build a sizeable operation, probably because they are more well known brands and bigger in size than these smaller/regional airlines that not many people know of like OLT.
Then what I mean is that it's the smaller, less recognised airlines like OLT who find it hard to build up successful operation, not airlines in general.
Although this may be no/very little fault of SEN, which I believe to be the case, it might be an issue for SEN in the future since it may lose traffic for reasons beyond their control since we've established that Ryanair and Monarch flights etc. are not going to happen and it's instead going to be relying on these smaller airlines who are finding it harder to set up.