The software was tested. It was tested with devices that had properly working wi-fi chips, because that's what it was designed to work with. You're right, Apple didn't test it with defective hardware, because any defective hardware would be replaced by Apple.
Your analogy is ridiculous. The two systems you mention have nothing to do with one another. One is periodic maintenance. The other is an authorized upgrade. A better automobile analogy would be if Ford provided a FREE fuel-injector upgrade, that when put into a very, VERY small percentage of vehicles that had defective combustion systems, caused a noticeable dropoff in fuel effeciency. And if the vehicle was still within it's warranty period, Ford replaced the ENTIRE vehicle for free. If it was not, then Ford offered to repair the problem at a very low cost.
That's an apporpriate analogy.
And as far as Apple offering the solution of "bake your iPhone and see if it works; if it doesn't then try freezing it" ... Apple never said such a thing whatsoever. Apple has NEVER suggested end-users perform that kind of maintenance on their devices. You are obviously confused. You are assuming that the solutions offered her, by other customers just like yourselves, are in ANY WAY SHAPE OR FORM endorsed by Apple.
This just proves that you have no real understanding of the issue.
My 'bottle' analogy was perfect, actually. The wi-fi chip is rated to handle a certain amount of power. Non-defective chips have no problem with that much power, and so their Wi-Fi never gets greyed out by the new iOS. But the defective chips can't handle that much power (even though they are supposed to), and so overheat/burnout/etc.
The power is the water, the chip is the bottle. Simple analogy.
You're frustrated about the situation. I don't blame you. But demanding a recall over such as small, small percentage, when Apple is already replacing defective items within their warranty period for FREE...
Free. Read that again. No charge. Gratis. Complimentary.
Only if a device is outside of it's warranty (i.e., the time period in which the device was promised to work as advertised [written guarantee of the integrity of a product and of the maker's responsibility for the repair or replacement of defective parts]) does Apple charge a dime for any service for this issue. And instead of simply repairing the issue, the replace the ENTIRE device at a 66% discount.
Name a company that offers to replace the entire product, at such a discount, even after the warranty has expired? They even offer that for situations that are inarguably customer-caused damage, like salt-water.
You claim Apple is recommending 'bake & freeze' fixes? Prove it.