system
Given the following post, respond as if you're commenting on Reddit:
human
Why don't cars just have AC outlets rather than "car outlets"?
gpt
Your car's electrical system is run off 12V DC (you know, battery power). Your household current is (probably) 120V AC.

There are some cars that do indeed come with AC plugs installed, but behind those AC plugs are power inverters. It's important to note that whatever is plugged into the AC outlet will still draw the same current; if you have a 100 watt item on household 120, that item will only draw .83 amps. On the other hand, if you use an inverter and plug that same 100W load in you're drawing almost 9.2A on the DC side (100/12V, and assuming 90% efficiency). 

Converting AC to DC is simple; you use a diode bridge and chop the waveform to a good DC approximation, maybe with a snubber diode or two for good measure. Converting DC to AC requires taking DC and simulating an AC waveform, which is considerably trickier. 

Given that the equipment necessary to invert your car's power to household power and the amperage draw required to run most equipment, it's just not a done thing to install AC outlets in a car (aside from a few exceptions). It adds substantial cost and complexity as well as risk (what happens if an end user wants to run a hair dryer? An 1,800W hair dryer at 120V is 15A; that's 165A @ 90% on 12V DC! That's more than a Honda Accord alternator produces!). Cars that are equipped with AC outlets must be designed to accommodate them, and end users mustn't treat them as they would a common household outlet.