A form of valid ID is such a hassle to get because it's used, pretty much everywhere, as an authentication token. It has to signify several things about you, in a way that anyone looking at it can legally use to cover their rear's with.
They always contain the following:
- Photo: A way of visually verifying that whoever is holding it is the person that was there when it was issued... (Yeah, how do they do that if you no longer have a current (valid) photo ID? Well, that's their problem, not whoever's checking the resulting ID.)
- Age: Are you over 18/21 so you can do Adult restricted things? (Porn, Controlled non-prescription drugs, etc).
- Name: A valid name to use in case you need to be found for some legal reason.
- Backer: What authority previously verified your information? (And who to contact to get in touch with you if it doesn't also list an address)
If you're getting a state ID, please remember to check your state DMV's website, as it will usually list the requirements for a driver's license/state ID. Usually the verification information for both is the same thing, save for passing a driving test.
Also, the reason the con badges are not valid proof of ID for adult venues is that there isn't actual validation of the 'provided image' on the ID. You could submit a photo of anyone, or more often, a custom image (like your avatar here). Then there's no way of verifying that you are actually presenting your badge. This also logically explains several policies regarding lost badges (in case they're intentionally misplaced).