With MacGruber making a dismal $4.1 million at the box office this weekend, Saturday Night Live's Lorne Michaels is learning a valuable lesson: Fool me once, shame on you. Fool me twice, shame on me. Fool me over and over again, consistently, for two decades, including a Stuart Smalley movie for crying out loud, shame on you again.

MacGruber got almost nothing but positive buzz after its South By Southwest premiere in March. It now has a 52% rating at Rotten Tomatoes, which isn't a great score -- but it the 4th-highest among all SNL-based films. Only The Blues Brothers (84%), Wayne's World (84%), and Wayne's World 2 (59%) got more favorable reviews. Meanwhile, Shrek Forever After has about the same Rotten Tomatoes rating as MacGruber, yet it made $71 million this weekend. What's the difference? Among other things, the Shrek franchise has a lot of built-in goodwill, while the SNL franchise is one of the most hated in all of moviedom.

At this point, it would seem that an SNL movie's actual quality is almost irrelevant. The bad ones have poisoned the well so thoroughly that audiences are almost irreversibly skeptical. They expect SNL movies to be lousy. The brand is almost as tainted as National Lampoon. After SXSW, when I wrote my MacGruber review for Cinematical, the comments people posted showed their incredulity. One commenter insisted -- anonymously, of course, as is the way of cowards -- that my positive review MUST have been bought by NBC/Universal. Mind you, this guy hadn't seen the movie, like I had. But it was unfathomable to him that MacGruber -- or any SNL movie -- could be funny.

That viewpoint was expressed repeatedly on Twitter and elsewhere, and the movie's lame trailers didn't help allay people's fears. Seems like everyone I know who saw MacGruber at SXSW and liked it later said, upon seeing the trailer, something to the effect of: "Wow. I would not see that movie based on that trailer. And I saw the movie! And liked it!"

Reviewers took pains to point out that yes, most SNL movies prior to this one have been awful, and yes, the MacGruber SNL sketches are short and repetitive. That's why it was smart of the filmmakers not to simply stretch out the 30-second joke for 90 minutes, but instead to turn it into a parody of '80s action movies. That's why we were so relieved to find that, unlike nearly every other SNL film, this one didn't appear to have been slapped together hurriedly to make a quick buck.

It didn't matter. After debacles like The Ladies Man, It's Pat, and Superstar, people weren't buying it. An opening of $4.1 million! That's the worst debut of the year for a film playing on more than 2,000 screens. Even Our Family Wedding, with Carlos Mencia, did better than that, and literally not one person on earth wanted to see that movie. People didn't just not see MacGruber. They didn't see it with a vengeance. Speaking of which, Furry Vengeance is another movie that opened better than MacGruber.

Here's the state of things. With a $4.1 million opening weekend, MacGruber will be lucky to make $20 million total. Walk Hard: The Dewey Cox Story was a similar film with almost the exact same opening on the same number of screens, and its final gross was $18 million. That means even though MacGruber ranks 4th on the list of best-reviewed SNL films, it will be 9th in terms of ticket sales. Even A Night at the Roxbury will have been seen by more people. That ain't right.

There have been eleven movies based on SNL characters. (We're not counting Office Space, from which some characters first appeared in Mike Judge's animated shorts on the show.) Here are their Rotten Tomatoes ratings and their box office grosses, adjusted for inflation for easier comparison. All figures from Box Office Mojo.

The Blues Brothers (1980) - 84% - $168 million
Wayne's World (1992) - 84% - $234 million
Coneheads (1993) - 31% - $40 million
Wayne's World 2 (1993) - 59% - $92 million
It's Pat: The Movie (1994) - 0% - $0.1 million
Stuart Saves His Family (1995) - 28% - $1.6 million
Blues Brothers 2000 (1998) - 46% - $24 million
A Night at the Roxbury (1998) - 11% - $51 million
Superstar (1999) - 34% - $47 million
The Ladies Man (2000) - 11% - $21 million
MacGruber (2010) - 52% - probably less than $20 million