Now, English is about as good at following rules as a toddler on a sugar rush in a petting zoo, but we’ve got a pretty good thing going with “A before words that start with a pronounced consonant, an before words that start with a pronounced vowel.” Why would you want to mess with that just for one profession?
Tabula Candida 
Oh yes, so agree with this. Also “hotel”. If you pronounce the H don’t use An. If, on the other hand, yer a bit of a geezer then fine, you can use phrases such as “awright guvnah, where to? A confrunce at an ‘otel? I know the place… So yer some kind of an ‘istorian or summfin’?”
Yes, the one acceptable exception!