SIDE NOTE:

Psychologically, repeated usage of the word "obviously" is very often a sign that portends to attempts at manipulation and gaslighting...

Obviously!

Police are often trained to queue into the repeated usage of the word "obviously" as attempts at obfuscating and manipulating the description of events.

Anyways, jokes about "Obviously!" obviousness aside...

I suppose I'll have to say: NTA.

So ya, if it makes you feel better, I don't think you're technically an @ hole here. But... there is an issue you are missing!

From a business perspective... I think you might be seriously missing out on a lucrative opportunity!

I say that because you said: "used the same argument all the other customers did".

Which basically means, according to your own words:

All of your customers are frequently arguing that there is not enough entertainment in your establishment for children? That's a highly unique universal-complaint from all customers!

It means that all of your customers go to your establishment with children in tow, and you're not properly serving all of those children on your business property, nor even attempting to make profit from all those little whipper-snappers running around!

Chuck-E-Cheese would be HIGHLY disappointed in you!

ESSENTIALLY... if that's what ALL of your customers are actually saying, as you are saying above, then your best bet is to actually...

LISTEN to ALL of your customers!

Seriously, why are you not listening to all those united complaints?!

And then proceeding to:

A) Better childproof your business area, since it has so many children running around based upon your description.

B) Better finding better ways to make a profit from all those kids on your business premise!

Because when it comes to tons of bored kids running around a private business...

That's a friggin serious gold-mine in the making you are sitting upon, and seemingly ignoring all the signs and vocalized complaints!?