KLM like BA at LHR used to have a near monopoly at AMS. The competition was without feeder flights and KLM could operate its hubsystem with relative ease.
There are plenty of cases like this worldwide, SQ, CX, EK (or the ME3 for that matter), etc. A sound homebase and very little competition. SIN has changed in the last few years with the rise of LCCs in SE Asia.
KLM is looking at the same form of competition, but with some major players entering the arena. Easyjet and Ryanair will be eating away evermore at their European business and the likes of the ME3 will be canibalizing the Mid East, Far East and Oz routes.
The results are already visible: MH was, even before the two tragedies of last year, seeing their customers switch. Probably some others faced the same. Prices have dropped to historic lows and KLM has for the first time this century announced lay offs.
AMS can’t deny airlines the right to use the airport as long as the capacity is available. KLM has no monopoly rights and is scrutinized over this by the Dutch government and the EU.
The situation gives airlines the possibility to enter into alliances to facilitate feeder flights from all over Europe to AMS and onto their flights. Maybe not as convenient, yet, as KLM, but definitely cheaper and often at comparable service levels.
BA so far has escaped this form of “low cost” competition because of the shortage of slots. No one in his right mind would fly in or out of any of the 5 other airports to or from a BA flight at LHR. This will for some time to come effectively counter the competition and will keep BA in a comfortable position. A third runway may seriously change this.
EU rules will not let BA gobble up the increased capacity. It is far more likely that the capacity increase will go to the competition.
The opposition by Mr. Walsh in this sense is not that unexpected.