I think it's superb- what's not to like? Mothers and fathers can introduce their littlies to theatre, which hopefully will instil a great love of it in the little folks who are our future audiences and it gives parents of small people the opportunity to get out, enjoy some culture, remember who they are and still be current to socialising where it's not all about the kids, which is surprisingly difficult, because whilst some places are baby and toddler friendly some really aren't and the tutting and glaring at the slightest noise of movement does get a bit wearing after a bit.
I'm assuming if you don't have small kids you'd not be going to this, so not sure what the 'unfair' aspect of it is, but we also need to remember that originally theatre was a very audfience participation raucus event, it's only become high-brow in the last 200 years or so. I'm all for it pesonally x