my first thought is that is good,
my second thought maybe its bad.
otto, I don't see any reason a cat can't have a taste of yogurt now and then as a treat. I just wouldn't let them eat too much at a time. Mine will eat anything so I don't give them much of the prepared human foods. Some cats are dairy intolerant so that could be an issue to watch out for.
True unsweetened plain yogurt tastes like butt though IMO; sour butt to be specific (needs fruit or something added). So if the yogurt tastes good to you, its probably not good for your cats.
When my baby (cat baby), AC, had a fairly serious infection, the vet gave him some heavy duty anti-biotics for it and actually recommended that if they upset his bowels, we try giving him some plain yogurt if he'd take it. Just a little, like a teaspoonful to help replenish his inner flora. It worked rather well.
And now, Missy, my former street cat, will scavenge just about anything if you let her. Since my son gets yogurt fairly often for breakfast, that means she steals a fair bit only she steals the sweetened fruit-flavored variety. That's not by my choice though.