Only one rental agency in ANC, Dollar/Thrifty, offers studded tires on some vehicles, and those only first-come, first-serve and for an upgrade charge.

IME, the stock (usually all-weather) tires on new vehicles get around just fine (though if you got an Altima with sport tires, I'd be a little less happy, too!). In fact, the first two winters I had my current car, I didn't even bother getting studded tires. The only place studded tires helps is in starting from a dead stop at a stop light where cars have been idling at the light and melting/refreezing the ice and snow. It doesn't really noticeably affect general handling or stopping distance (maybe a tad).

If studded tires are not an option next time you rent, I'd take an upgrade to an SUV. The four-wheel-drive gives much better traction and handling, and the stock all-season tires on those kinds of vehicles perform VERY well on the streets of Anchorage. I'd much rather be driving a Jeep Grand Cherokee with stock tires than my car with studded tires!

As for why rental agencies don't stud all their cars: at $100-120 per tire, four tires per car, and several hundred cars, that could represent a cost of over $150,000 to a typica agency, and that's in months when most agencies up here are really operating in the red due to low demand, depressed prices, and low fleet utilization (for some agencies, the cost to stud all their vehicles would exceed their monthly revenue!). They're already renting the cars out below cost (at-cost would be about $30/day at 80% utilization [not including staffing/facility/etc.], and most here are operating in the winter closer to $15 or $20 at 50-60% utilization), so adding extra expense with virtually no additional return is not something they're really enthused about doing.

I'm actually unaware of any city where all rental vehicles are regularly studded at no additional charge to the customer.