I think the point is that it's time to start taking the power back from large corporations who feel nothing but contempt for the same people who keep them in business.
Even if it's in such a small way as this, it's still better than firmly planting your head in the sand, with your ass in the air and a nice sign on your back that says,
"Please corporate America, keep railing me!"

If we all just sit back and let big business throw their weight around, and silence the consumer whenever something is written that doesn't fit in with their marketing scheme, then we'll reap what we sew, and continue to get sub-par products as well as the continuing degradation of customer service/support for said products.

And I also think in this example, if you read the letter from Dell's council, you can't help but notice the total lack of respect and general tone of contempt that saturated every paragraph. Not to mention the underlying belief that "The Consumerist" wouldn't have the intelligence to counter any of the empty threats made by Dell's council.
That alone should be enough to fire-up most intelligent people. It was as if "Mommy Dell" was wagging her finger in their faces like "The Consumerist" was nothing but a naughty little boy.

WE, the "consumer", are the ones that keep these people in business, and it's up to US, the "consumer", to hold these people to the standard that they pretend to hold themselves to in order to get us to buy their products.

If there was no problem with Dell or their products, then I think it's safe to say there wouldn't be an issue here, but once something is exposed from the inside, you see them scramble like roaches in the light to do a little damage control before something bigger gets exposed, or God forbid, someone else might take a closer look at Dell and decide their money might be best spent elsewhere.
On a large scale, that could be disastrous for their already falling profits.
After all, the profit is what they're all about.
The customer is nothing but a money conduit.

In general, I have no problems with Dell... because I never bought any of their products, but I can assure you that if this letter came from the council of any corporation that I buy from regularly, I would have to rethink any future purchases with them.