At which point I note that "Language is not logical, nor is it consistent, nor should it necessarily be either". :P

Language contains exceptions after exception because noone ever assesses the entire system at once, and language is an entirely arbitrary construct anyway. "And" by any other phoneme would still be a conjunction, and "And" need not be a conjunction if it's better serves the speaker to be a preposition.

In short, stop being a grammar nazi :P