From the restaurant owner's perspective there is no benefit of slow or bad service. That means guests are taking up room without spending money. It makes much better sense to be speedy in giving your guests attention and service, as this gives you more sales, more margin for error, and most importantly much happier guests. They can still focus on the socializing and being merry.
It's just there is a difference between "slow service" and, you know, taking needed time.
Sure, some times it can be slow, at any place or country. But the thing described in the parent comment is just either a hyperbolization (my bet) or some unfortunate coincidence.
