I would disagree it's harder. It's trepidatious, but that's not the same.
We're in the middle of taking all our internal apps talking to a single huge Oracle database, and giving each app its own cluster of two PG boxes. Nothing has to play nice with anything else - that alone suddenly makes life ridiculously easier.
We have expensive paid Oracle support, who do PG as a sideline. But we've yet to have occasion to call them about PG.
We asked Oracle for a quote for two replicated mysql servers for HA. Because they were VMs we got a quote for 3 years that was 410,000 SEK (almost $50k). So we built our own replication solution with mariadb for free.
But yes, it's good to have the option of doing it yourself :-D
(For our few services that run on MySQL, I'm really hanging out for MariaDB to make it into Debian and hence Ubuntu, which is what we run on live - a mix of 12.04 and 14.04. Oracle runs on our last two remaining Sun Niagara SPARC boxes. We will be killing our last Oracle this year.)
So I can totally imagine people being fired for getting in over their heads and messing something up, maybe repeatedly.
On the other hand, I've seen techs be banned from a client environment while dealing solely with proprietary software too.