While English is, and always has been, a "work in progress", evolving all the time, there is still a lot to be said for speaking confidently and concisely.
As a single parent I made myself very unpopular by insisting my three spoke "proper", no ums, errs or likes allowed. It wasn't only the sproggs who objected, other parents also passed negative commentary on my constant harping about it.
Now that they are all grown they have found that their speech has greased their way in the world, good careers, regular promotions and a healthy respect from all those around them etc, and they now thank me for it.
Humans stand out from the animal kingdom for their communication, why be sloppy about that?

This was taken from a high school text
"Changing Australians: a Social History),
for year 12 students as an example of -

"Learning the lingo."

"He said, "Fellow Australians, both old and new.
I'm glad to see yus here for this important
ceremony. In welcomin' yus, on behalf of Council
though. I would stress one point, important to all
of you, who are wanting to be nationalized. I
would urge you all to learn to speak English
properly. I know that, in my own particular line,
which is plumbin', I often have the greatest
difficulty in understandin' what some of yus are
talking about when you endeavour to describe what
is wrong with your sinks, baths, or cisterns - as
the case may be. Now this is only one instance of how
important it is for reffos - er - new citizens - to
learn to speak English properly, I mean ter say, if
you can say "comment tallez vous" in your own tongue,
isn't it just as easy to say, "How are yus going,"
in English? So listen to the old Aussies around yer,
and in next to no time yus'll be spoutin' English
left, right and centre, just like the best of us."

Two common pretexts for slovenly English:

* "The language evolves, Mate"
* "Oh well, they'll know what I mean"

The three-word slogan for promoting slovenly English:

* Ignorance is strength

A truth about language:

* Meticulous thinking requires meticulous language

A horror I read in this morning's on-line Guardian:

* The noun "illicit" when the fool meant the verb "elicit" (Yes his thinking was slovenly too - he was mistaking the sugar coating woven into Islam for its message.)

There aren't many things that grate me more than the academic "um". For people so educated using this abominable uttering is a clear indication that education does not improve intelligence.

There are err's from yiz and youse but then there are outrageous foreign accents that border on Italo-Espanola.

Hence we have sexy Sofia severely outing Ozzy's Own Julia Guillard's ACTU-cockney accent http://youtu.be/bBA7Ashxfig 20 seconds in. Then Sofia indulges in severe R rolling from 1 minute, 5 seconds. VerrrrrrEEEE Gud.

The way Sofia trills "stump-jump plow" is heaven :)

I agree. The level of articulation is quite bad. I particularly noticed this when at an international airport recently, and standing beside me in the queue were some Australian teenagers: "it's like, you know, and I was like, you know, then it was like, you know." My goodness.