Respectfully I disagree with you.
Tethering is very much a service offered by the carrier. Yes it is built into android but the data you pay for according to your contract if you don't have a tethering plan is specified as data that will be used on your device and not connected to another device. The free tether was removed from the Nexus S 4G in an update because it violated Sprint's ToS so apparently Google feels that if tethering is banned from the contract with the carrier it is not something provided by Android but is in fact a service offered by the carrier.
I'm not picking sides in this but I really liked this analogy I saw somewhere:
My water utility sells me metered water for washing dishes, watering the lawn, showering, and other limited purposes.
The utility offers a Tasting plan for an additional monthly charge. Under this plan, I am allowed to use the water also for cooking and drinking. (Even though my water use is metered, and each gallon of water for cooking and drinking is delivered by the same pipes!)
Dear customer: our records indicate that you have been using water for cooking and/or drinking. Please upgrade your water rater plan to our convenient Tasting plan that allows for this usage. If you continue to use water for cooking and drinking, you will be signed up for the Tasting plan automatically.
I think the Tasting plan is just a fee that they made up. It isn't a service they provide. They just want more money from me. I've got a workaround of using a container to obtain water from another room for the purposes of cooking and drinking.
Some people shout: Theft of service!
But what service? They're already delivering water to me, and metering it, and I'm paying for it, and its delivered by the same pipes!
Some people shout: but you signed an agreement and using the water for cooking and drinking is a breach of that agreement!
Ask a lawyer about the term "unconscionable contract".
Nobody in their right mind would agree to this if they had any actual choice in the matter. Just because they have the power and can force you into paying this ridiculous fee or doing without doesn't make it right.
I say that this Tasting "service" is no service at all, it's just a fee for delivering nothing at all extra to me. It's a case of the utility wanting something for nothing. Yet people seem to think it is somehow wrong to use the water I'm paying for for drinking or cooking unless I sign up for the more expensive Tasting plan.
In order to add legitimacy to their Tasting plan, the water company says that the Tasting plan is actually delivering something: it includes an additional 2 Gigabytes of water per month, giving you 4 total Gigabytes of water.But what if I only need 2 Gigabytes of water and therefore my existing monthly 2 Gigabyte plan is plenty? The water company already charges $10 per extra Gigabyte of water I use over the limit. So if I used excess water, it's not like they wouldn't get paid.
Furthermore, once I sign up for the Tasting plan, they don't make any distinction between water used for drinking/cooking and water used for other purposes. I could use 3/4 of it for tasting, and 1/4 for bathing/dishwashing. Or any other split. Or all of it purely for tasting. So then if I paid for Tasting and used only 2 Gigabytes of water, which I already had paid for, then why did I need the Tasting plan?