Because the Universe Still Hates You: National Lampoon's Vacation Getting Rebooted
John Francis Daley and Jonathan Goldstein are set to direct it based on the script they wrote themselves. Their big qualification is that they wrote Horrible Bosses last year. This does not qualify them to make this film. Nothing qualifies anyone to make this film. This film is going to technically be a sequel, setting up Rusty (played most famously by Anthony Michael Hall, and someone different in every subsequent film) as a father taking his own family on vacation. They'd do better by just getting Chevy Chase to play his old character, and kidnap his grand kids to go on vacation.
There is a sublime hilarity to Chevy Chase in the 1980s that simply cannot be replicated by any writer or by any actor. And while it's tempting to raise up the old demand that Hollywood just make something new or original, I don't think that's necessarily the root of the problem here. Comedies anchored by a comic are one of the sorts of films that we actually do get non-sequels and non-reboots for, but the problem is that most of them are just abysmally non-funny. Personally, I blame Adam Sandler.
On second thought, there is one reason, and only one reason, that might justify this film's existence. These guys were involved with Horrible Bosses, so if they manage to get Charlie Day to star, in that case, I will consent to acknowledging its existence. But only then.