There are a couple of reasons why I often address these letters to writers. The first is self-serving. It is the thing I know most about. The second is more specific to the movie you wrote. If it ain't on the page, it's unlikely to be up on the screen, especially with a comedy. And Snatched is so thinly drawn, you'd have a hard time squashing a bug with it.
I won't pretend I've liked your earlier work, The Heat or the rebooted Ghostbusters, both of which struck me as tepid and lazy examples of the lowest common denominator kind of comedy, that leans far too hard on star power and not nearly enough on good writing. Even if you have actors as sharp and well attuned to one another as Steve Coogan and Rob Brydon in The Trip, or someone who can carry the emotional weight of a whole film like Jenny Slate in Obvious Child, comedy still needs a strong script to be anything other than the absolutely forgettable nonsense that is Snatched.
With a film like this the plot doesn't really matter, it is simply a contrivance to create weird situations that are hopefully comedic. But here's a thumbnail sketch: Amy Schumer is a hapless thirty something whose boyfriend breaks up with her, so she drags her mother Goldie Hawn along on a South American vacation. From there an increasingly unlikely set of circumstances ensue.
That this is the film that Goldie Hawn chose to make her return in is frankly baffling. She is wasted as a parody of a lonely, divorced mom who hasn't had sex since her husband left. She is also so hamstrung by the way her character is written that she is nothing more than a foil to Amy Schumer's feckless and completely self-involved disaster. In fact, every character (except Schumer's) in this film barely registers as human, inasmuch as they are nothing but a collection of paper thin clichés that show up when the plot requires, and then disappear just as quickly. Joan Cusack and Wanda Sykes as a platonic couple are a particularly good (bad) example of characters that appear out of nowhere in order to help navigate a plot point, and then are literally driven off stage once their usefulness has concluded.
To be fair, Snatched is not directed at me at all. However, I went with my wife Sarah, who is a thirty something directly in the crosshairs of the marketing campaign, and other than a couple of mother/daughter moments that resonated, Snatched fell flat for her as well, and for the same reasons.
The caveat to all this is that, perhaps of all genres, comedy is the most specific to personal tastes. There may be something here that I'm missing, or someone else might find more interesting. But that's probably me trying to assuage my own conscience about so thoroughly disliking what you had a hand in creating.
Hopefully, next time it will go better for both of us.