Re: The "why" in your question is complicated
Ho Hillbilly, take another puff off them cigars and relax. 90 percent of Dominicanas coming to Europe, prostitutes ? Where did you get that info ? Beg to differ with that and with your socalled "socialized benefits". I dare you to ask that Vietnam Vet if he would rather have them "socialized benefits" or standing in line for the soupkitchen and begging in the streets.
His devotion to the Stars and Stripes cost him his legs and now he has to beg for food. Don't misunderstand me, the US is a great country and I had my best child/teenage-years there.
Here in Holland a big chunk is taken off my bruto salary and diverted to these "socialized" social services. The unemployed have an income, affordable healthcare is maintained, everybody is happy, etc. etc. And I don't mind (much). 'Cause if criminals stopped plundering society tomorrow, I'd be out of a job. No matter, I don't need to beg on a streetcorner, I can claim social income.
Now the Dominicanas. Most here in Holland at least, got here through valid marriages, with only a few through illegal migration and pseudomarriage. Yes, there have been arrests of Dominicans in brothels. But the numbers are small. Most estimates of DR citizens in prostitution I know of, speak of nowhere near the figure you gave. I will not go into detail, but our intelligence talks of organized crime, girls lured under false pretence especially to Germany, Spain and Switzerland. A big prostitutionring was busted two years back by a Spanish TV-program, jeapordizing another big operation by Europol. A Dutchman was arrested along with his compadres in the DR and Spain.
Wim, het is inderdaad moeilijk, yes it is difficult. Charly, das stimmt nicht, somebody told you a fairytale. The Schengen-accord stipulating travel and traffic into and within the EU is strict, also for Spain. Still it is not impossible to get that visa.
Make sure your papers are in order when you apply for visa, have someone from Europe invite you and mention in that invitation that the host will guarantee you will not be a burden to the state.
If marriage is the goal, say so and cooperate with the police in your country as they investigate if you have sufficient means for a household. But equally important, get on that consular employees case, phone him or her, so they know you as a host are following events closely from Europe. These consul/embassy-boys tend to get lazy out there. Get on their skin !
Wim's problem is that Belgium has become a prime target for both fake and legitimate refugees and economic migrants, wanting to get to a.o., the UK. Also Belgium, had sort of an general amnesty for illegal migrants a few months back and services there have an enormous backlog of applications. That gave trafficjams and a massive influx of illegals from all corners of Europe, claiming to have lived in Belgium for years, now wanting a pardon. Houdt moed, Wim.