Personal guess: because switching DBs is expensive and if it works, why bother? I personally LOVE pg over all other choices, but I've got some 5-year-old apps

Personal guess: because switching DBs is expensive and if it works, why bother? I personally LOVE pg over all other choices, but I've got some 5-year-old apps sitting on a little mysql DB and no intention to move them. Dbs are small, performance is good enough, cost of instances wouldn't be very different on PG, but cost of moving everything over is probably a week or two of work that would be pretty hard to justify given the current situation.