Finch wants desperately to be a good boy.

It learned all the movies it wanted to be. Rain Man; 2001: A Space Odyssey; E.T. The Extra-Terrestrial. It had a beloved breed in Tom Hanks, who established his canine flick bonafides with Turner and Hooch. He won a couple Oscars, too.

But Finch ultimately is a good argument for why the MPAA needs its ratings system fixed. Because while it is rated PG-13, Finch is not a movie for audiences 13 and older. I’d say 16 and under.

How else to describe Apple’s latest film? It feels like Castaway met Wall-E and they went off to raise My Dog Skip — without the originality of any. Finch decaffeinates and sanitizes so many crucial scenes you’d think Disney made it (right down to physical comedy that’s just plain Goofy).

Hanks reprises the deserted-island role he made so memorable in Castaway. This time, the universe wants his character dead by solar flare, which has already wiped out most of the planet. Rightfully concerned that his irradiated days are numbered, Finch builds a robot to care for his dog.

While those plot details might be trickled out in an adult drama. Finch vomits forth those irresistible plot points almost by the first half hour. From poster to trailer to opening scene, Finch wears its cliches proudly and telegraphs its messages as clearly as Morse, which is almost a charm in itself.

Because there’s no hating Finch. I wept during it, but almost furiously so: It’s like a rescue shelter commercial set to Sarah McLachlan: Either don’t watch or get a tissue, because your heartstrings are going to be mercilessly plucked.

And it’s hard not to watch anything Tom Hanks does, even when it’s just him, a CGI robot and a rescue dog named Seamus, a terrier mix who looks a lot like my rescue mix. I was ready to love Finch. I wanted to love Finch.

But then Finch started misbehaving. For starters, Seamus plays a dog named Goodyear. Goodyear? The film gives some contrivance for Goodyear’s name, but come on: At least know a good dog name. You know, one that a dog would recognize and wouldn’t sound like product placement. Say, Seamus.

And for the robot, Jeff (again, ??). The movie quickly establishes that Jeff has only 72% of the information about the world that our hero, Finch (Hanks), meant to upload. A sudden dust and radiation storm cut the upload short, propelling our band into a wacky road trip.

There are many details to follow in the movie, but it’s all downhill from premise.

Or maybe not. Perhaps Apple, Disney and all major studios trying to stay in business view movies not for their teenager-and-older subject matter, but for their teenage-and-older consumer matter.

Because the movie ratings system is a grim numbers game, as the Motion Picture Association of America has confused its ratings as a seal of approval from the film industry — or a specific movie.

Your movie have smoking in it? PG rating. More than two “fucks?” You got yourself an R rating, buster. Showing pubis, or, worse, showing it in a sexual context? You’re flirting with an X rating — a death rating outside a particular demographic.

So why don’t we in the media get out of that absurd system? Can we not tell audiences who the movie is for, in terms of subject matter, instead of using Hollywood’s definition of age-appropriate viewing, which is a consumer-based metric?

Because Finch is a fine family film, full of fine lessons about friendship, family and the meaning of consciousness.

I just expected it in an adult film.