The answer to that is simple
It is the best aircraft for the job, and it is notable that the most profitable low cost carriers operate it, rather than the European equivalent.
Well EasyJet is pretty happy with the Airbus A320, aren't they?
Moreover in the Ryanair CEO last declarations good arguments for the A320 come out in respect of the 737.
The -800 is probably cheaper as initial investment than a A320, and the extra 9 passengers over the A320 180 limit is a good point for Ryanair.
Moreover Ryanair is coming from Ireland where, along with UK, transitated to the european narrowbody later that continental EU (Scandinavia didn't made it at all), and for a startup low cost carrier to find already in place qualifiesd pilots and technician is a good point.
This also mean that the new Boeing's narrowbody (797) will not automatically get its granfather legacy (and Boeing already argued that the -800/-900 will remain in production...)
Easyjet has A320 series it is true, but I think that Stelios Haji - Ioannou's comments and reported opinions on the adoption of Airbus aircraft are interesting , but I would not offer my own interpretation of them.
The fact that the 737 sits closer to the ground is often overstated.
With every iteration of the CFM-56 it gets more efficient and while intuitively it would appear that a new engine, particularly a geared turbofan will deliver a substantial improvement in efficiency, it is the total life cycle costs that are usually the main determinant.
An example is Allegiant who operate the MD-80.
At first look this aircraft is a fuel burning dinosaur and on its variable cost's the numbers will confirm this, but its total life cycle costs are competitive.
Boeing in the meantime are eeking out efficiency improvements by cleaning up the airframe, and small incremental improvement's while not as sexy as a new engine do make a difference.
My hunch is that the 797 will be something looking the old ATMR and when the 787 has gone along the production learning curve, the resource will be available for its production and development , while Airbus will ensnared in the A350.
The A320neo is trying to buy some time for Airbus
Lets not forget that Easyjet went for the 737 and then switched to the A319 when they realised the error of their ways!
Ryanair didnt get Airbus aircraft as EADS told them to bugger off with their demands for getting the aircraft at a very very cheap price. Something Boeing were willing do to!
Also look at BA (i know not a low cost carrier yet!) they have always been big Boeing fans but even they were impressed with the A320s that they inherited from Caledonian. So much so that in the end they ordered A320 series aircraft themselves.
As a passenger i prefer to fly on an A320 series rather than a 737! Although just to prove i am not anti Boeing my favourite aircraft to fly on are the 757 and 747!
Easyjet got involved with the A320 series largely because of Andy Harrison
see the below from the Telegraph
"Stelios thinks Andy Harrison's performance is overrated," a source close to the tycoon said. "Over the last five years, Andy Harrison has developed a love affair with Airbus, spent $4bn (£2.68bn) doubling the size of the fleet, while he paid no dividend and the share price has gone sideways. The only thing that went up was the size of his bonus
One can only speculate as to what this "love affair" entailed and what the financial details were, but running two different types of aircraft and the transition costs are clearly not low cost and the shareholders will not get that money back.
It would appear (according to Stelios) that Harrison put his own financial interests before that of the shareholders so one could argue that Easyjet operates the A320 because of that.
BA are not low cost so that part of your argument is irrelevant.
Mike O'Leary like any rational businessman will look for the best deal, and he knows that most A320's are given away anyway courtesy of European taxpayers, but he really just wants the 737.
He is ,as I say rational.
I hear that you pal O'Leary is thinking about charging passengers for using airstairs! Apparently he is looking at charging £1 for each step you take! If you take them two at a time then you will be able to get a 50% discount on the charge!
2003 :Wizz was formed in Poland ,and purchases/leases a European aircraft
2004 Poland joined the EU
To buy/or lease an American aircraft while trying to join the EU may have appeared un European
As for making a success of it, no one really knows (apart from its investors) if Wizz is making any money.
Ebeneezer.....If I may interject, regarding your comment "Easyjet got involved with the A320 series largely because of Andy Harrison"
The Orange love affair with Airbus originated from an order of 120 x A319 at the end of 2002 under the direction of Ray Webster (Chief Executive) and Stelios (Chairman). Harrison (formerly of the RAC) was appointed in 2005.
It may be the perception of a reasonable person that my choice of words in my argument was innapropriate , but clearly this is a question of semantics, and misses the main point of my argument, which is further evidenced by the following excerpt from the article you refer to
"Ray Webster, easyJet chief executive, says that speculation about a 60%discount from list price is "a bit ambitious, but not far off". He adds: "I've been buying aircraft for 20 years and I've never seen a deal like this." Boeing has already hinted that the price went too low for it to stay in the running.
Therefore it, is resaonable to suggest that the purchase of the aircraft was decided on the calculated total life cycle cost of which the purchase price is a component.
In other word's it was the total package not the technical attributes of the aircraft, which returns us to my original argument.