'Want to come ' does not mean 'will come'.
I want to go on holiday to the Caribbean. And if you asked me in a survey did I want to go on holiday to the Caribbean I'd say yes. But I'll never go. It's not something I plan on doing.
That's because you can't afford to go to the Caribbean because when you arrive there with your six children no-one will pay to feed or house you for as long as you want to stay.
Want to come doesn't necessarily mean 'will come' but it probably means 'will try to come' if the conditions are right. Even if only 10% of that 12million manage it, the majority of them will be poorly skilled low income workers and with the birth rate among Turks currently at around 16 births per thousand of population compared to our 4.7 per thousand, (which is massively up from 2004 as a result of recent immigration anyway) that still represents a bit of a fucking problem. Turkey is a country with virtually no benefits system and you still see severely disabled and poverty stricken people and children scratching out a meagre living by selling trays of plastic combs on the streets to get by. You think they aren't motivated to try to come? Of course they are.
I am also angered that Turkey are being considered for inclusion into the EU, mainly because they aren't actually in fricking Europe. 
If Turkey was a human being and their body represented Europe and Asia, the bit that would be Europe would be about the size of one hand and half a lower arm. It's a joke.