[QUOTE=RudderTrimZero;11244192. These airlines do it in the hope that the completion will crumble. That is there only motive.[/QUOTE]
In normal economic terms, such conduct would be termed predatory behaviour , would have the intention of driving other companies out of the market (as you say ) but would normally entail the predator selling below cost and making losses for a short time until the competitors disappeared/went bankrupt. Here however the problem with your argument is that Ryanair has been in business with this method for 30 (? ) years and is very profitable.
I recall the late 70's when a MAN/CPH full-price return with SAS would be GBP 550 ( may not be exact, but a lot of money ) and all pilots could buy a villa on the Cote d'Azur with their salaries. It's that damn old pendulum.