I think it's more that he spoke up, and many of the men happily married to Dominicanas just keep it to themselves most of the time.
A quick look around DR1 will show many successful marriages and long term relationships. I'll admit that there are fewer of us women married long term to Dominicanos, but we're out there. I attended a memorial luncheon in SD for a girlfriend who died in March, and at least half the women there were married a long time [many decades] to Dominican men.
The truth of the matter is that those of us who married Dominicans, and are happy, are hesitant to talk too much about it to newbies in love, because we know the odds are against them. We don't want to feel guilty when things go wrong.