Your comment doesn't make sense, why in Hacker News should I show more respect to Walmart and JP Morgan rather than google or apple by calling the former legacy industry and the later big tech, and why are you so worked up about it?
Relying on the existence of one vendor with highly unportable and unmaintainable code carries its own risk and my post is asking whether it justifies the cost.
It also gives you the opportunity to use their mainframes advantages to the very max. Not the "common feature set" but the very "best features" you can get out of your tech choice.
I do the same, I have run PosgreSQL for more than 2 decades now and I don't care about portability to any other database, all of which I consider inferior (and yes, I do follow most of their releases).
Relying on the existence of one vendor with highly unportable and unmaintainable code carries its own risk and my post is asking whether it justifies the cost.