Me too. Fortunately my kids have out-grown soft play centres as these seem to be meccas for crap parenting.Boils my p1ss this, why can't people take charge of their kids (I have two myself!).
I'm the least aggressive person in the world but on so many occasions I got into a slanging match and nearly worse due to parents sitting and drinking coffee believing that it's someone else's responsibility to supervise their children which are creating havoc. There is undeniably a causal link between the proportion of inattention of the parents and the extremes of their little darling's behaviour!