From a US American perspective this whole situation is kind of strange.
Many moons ago I had some time on my hands so that I decided to do the FAA ATP written (ONE test). I had glommed a Jeppesen course book from a guy whose 'stovebolt 6' Chevrolet engine I had overhauled, plus I bought the latest version of the questions and answers to the test.
I holed up in my flat in Charlotte studying for one week straight, only emerging blinking into the daylight to take my evening meal in a cheap bistro.
When I was ready I booked the exam with a phone call, went in the next day, took it and passed with 93%. Total cost, about $50.
A few days brush-up in a BE-95 Travel Air ($800 for 10 hours, 'wet'), $100 for the examiner and I was an Airline Transport Pilot.
Another time, I needed an FAA FE license. Same story; one week living like a hermit with a DC-6 Flight Crew Operating Manual and the current Q & A for FE Reciprocating, followed by a trip to Burnside Ott at Opa Locka and another 93%. A few days of riding around in a DC-6 and then a practical test in a DC-7 and, presto, I was an FE! (Just to show the license to get into a certain African country, since I was only going to fly 400-series Cessnas.)
Now, for a JAR ATPL, I have to go to school from mid-November until the end of next June. I don't even want to think about what all this is going to cost, but it's going to be a case of leaking cash while waiting to become theoretically employable, every pilot's nightmare.
The (very expensive) JAR writtens are only available at certain venues at certain times, when there's no practical reason why one could not do them anywhere there's a telephone line to connect you to JAA Central, say.
Certainly from my time futzing around with the German LuftfahrtBehinderungsAmt (LBA) I got the idea they were trying to protect their local market from new boys trying to come in. And I think that might be the case with the JARs, that each regulatory body is thinking of how to put a spoke in the wheel of anyone trying to come in. It is just a sort of regulatory reflex, if you will.
The most galling aspect of this, as a Yankee, is that Europeans have relatively free access to a US license, when we accept their credentials at face value. Showing up with a US license in Europe is held to be a joke, on the other hand. Spare me the stuff about getting the US license off the back of a cereal box; there should be more reciprocity across the whole regulatory spectrum IMHO.
To go back to school after having flown as a professional for years is the only option, yes. I shall just have to get in line along with everyone else who wants a JAR license. It's not that I am being discriminated against.
A bigger question might be if this sort of thing being allowed is why aviation seems to be much more robust in the States, in many ways. I see some sort of situation where there is a small European market for pilots so that the regulators seem to be putting a brake on the supply of pilots rather than thinking of how to grow the market.