Throw another one in the "why was this even made" column. Parental Guidance is probably the only movie so poorly written and directed that it makes Marisa Tomei seem like a bad actress and Billy Crystal and Bette Midler appear to not be funny.
There's no reason to write an in depth review because there isn't really much of a film. With so many jokes you could make about how children were raised versus how they are raised today, the writers couldn't come up with anything better or more original while writing a decent story. I'd think any experienced writer would have to TRY to make a movie this bad.
Midler and Crystal are still who they are, so there are a couple of funny parts, but poor Tomei. She was so miscast and did so poorly in Parental Guidance that I couldn't help but feel bad for her. The only bright side to this movie being made is that Bailee Madison got to be in and develop in another film. She's an OK actress, and might turn acting into a career at the rate she's going.
Parental Guidance doesn't have anything offensive, nasty, mean, or funny, and was pretty pointless and very unoriginal. Maybe a decade from now when Parental Guidance comes on TV late at night I'd say it would be good to watch. Otherwise, you'd be wasting your time watching it.