Your best bet to emigrate is when you're young and single. As soon as another person is involved it becomes difficult as you each will have your own views. When kids are involved it becomes impossible except for specific time frames. There are many that are in this boat - many that have planned to send kids abroad for tertiary education but take advantage of the life here while it still exists (in terms of private education, support structures, help- the whole 'bubble')
If you are not in one of these bubbles and/or otherwise unattached then I don't think much could or should stop you from leaving.
Just to put into perspective, seeing as I'm sure a lot of guys here are considering. If you can get into the netherlands on a rare skills visa (not impossible, many companies sponsor, if you have a masters+ education and are in your 30s, you'll probably get it) you get a tax break - essentially the first 30% of your income is tax free - the tax implications of this are massive.
With kids it becomes nigh on impossible. Even then, tertiary education overseas is outrageously expensive (google what it costs to send a kid to something like harvard if you want to puke) unless you are truly gifted academically (and I don't mean "I got 7 As" I mean, "I do 3rd varsity level maths and I'm 14" gifted). Realistically if you have kids and are not sitting on a net worth >30m, the best bet is to get them into the good SA universities and hope they do well enough to apply for post grad study overseas on scholarships. Depending on the field post grad is likely to be a requirement anyway for serious career advancement.
TBH the top end private schools and good public schools in SA can compete with anything overseas has to offer, and undergrad education is all so cookie cutter that you're not really gaining more by going to an elite school over a decent local unversity anyway - indeed for certain fields of research SA universities are legitimately the world standard.
