Accidents made of Accents

Veronica Lee of the UK Guardian recently suggested that the stage get rid of all accents. Her argument was that it is better to have no accent on stage than a bad accent.
Snowe's First Law of Audio Drama certainly applies here, and that law is "If it distracts from the experience, it needs to go." That includes whether it is too little or too much production, scripts that are over or under written, and acting which is too heavy or too light.
The moment I ask myself about the structure of the production, is the moment I've been pulled from being involved in the story.

The one thing that makes audio drama a little more unique than stage however, is in the aural medium voice IS your costume. Characters that sound too much alike also throw the listener out of the experience as they try to understand who is speaking.

So what does this mean? If you're going to attempt an accent as an actor, get it right. If you have trouble with specific accents, but the Director needs you to play a regional or national identity go broad.
It's much better for an actor to focus on the cadence and pacing of an accent, than of the actual clipping, drawls, or dropped "h's". Different regions attack words and phrases in different ways. Try to go broad with your depiction. If you're attempting a Mexican accent, go for one who was educated in America but still has the simplest of accents from his homeland. Give people the flavor without getting yourself pigeon-holed into a specific location.
And in the worst case scenario, don't even try it at all. Some actors focus so hard on the accent, the central truth is lost in the words. The characterization must always be true to the story.
Of course, if you're going for a roughly-hewn comedy, all bets are off. The goofier the better.
If not, consider not!