RWL2013 has already showed you a method for using old versions of apps on old iOS versions.
It would run slowly and inefficiently, and my old MacBook can't run OS X Mountain Lion because, well, the hardware is very old. Same goes for Windows, there is always a minimum system spec sheet for all Microsoft operating systems.
Okay, so we're not talking newer operating systems but newer apps. Can you run the latest version of Photoshop on Windows 2000? Can you run the latest version of Safari, Firefox, or Chrome on a Mac running OS X Tiger?
Newer versions of iOS have newer APIs which apps take advantage of, and after years of development (iOS 3 on old iPods vs. iOS 6 on current ones) there is a massive difference between what those apps can do on each version. Apps for current iOS versions would not be able to function correctly on outdated iOS versions, simple as that.
You insisting Apple continue to provide legacy software, but why? Can you go into a shop and buy a version of Photoshop that runs on Windows 2000? No, you have to go online and probably pirate that old version if you want to do that. You can do the same thing here using an unofficial app repo on an old iOS device.
I don't complain I can't run all the latest software on my iMac G4 because I know that, although it's a nice machine that brings about feelings of nostalgia for me, it is frankly crap hardware wise compared to modern computers. Second generation iPods are the same. Unless you're emotionally attached to it, throw it in the bin and buy a new one.
There are around five of those every month, none of them ever gets anywhere. I dislike Apple's walled garden too... which is why I don't buy iOS devices anymore. Seriously just go get an Android device if you want to sideload apps.
This is where you insist on putting words in my mouth(or just really, really don't get what I am saying here). No, you cannot install photoshop onto windows 2000. But a windows 2000 pc can be upgraded to newer versions of windows. But te most important point is that I am free to legitimately and legally, without going through loopholes, install an older version of photoshop. In fact, adobe is happy to help you with older versions of photoshop and have made some of them free. Why? Because they are free to distribute (and sell, if they choose) the software. They don't have to go through some AppStore.
Again, you say I insist apple continue to provide older software. That is absolutely not what I have said at any point in our conversation. What I am saying is that I recognize the issue that the AppStore imposes; the fact that I am only ever legitimately allowed to download software from said AppStore. The fact that an ipa is available on some site does not make it legitimate. In fact, I would venture to say the fast majority, if not all, "legacy" ipa you find online are not legally obtained/obtainable. As such, the loophole that is available is not really an answer (not is it supposed to exist if Apple knew about it before dumping 3G support, but the latter is just an assumption on my part, albeit a safe one I think).
So again, since you keep misinterpreting my meaning, my issue is with the AppStore and how it is te limited distributor of apps. In this specific case I feel the customer loses, and again, this is why there is a lawsuit about it. You may claim no lawsuits gets anywhere. While you are free to make said claim, it would be an incorrect one. Users of the 3GS who were denied warranty service due to water indicator damages were just ruled that they were entitled to $200 for the repairs that they likely paid out of pocket. Apple gets hit with fines all the time, and are forced to change things to comply with laws. The EU is also looking into Apple's anticompetitive AppStore nature in Europe. The sampler lawsuits in the states isn't huge, but the eu looking into them is a pretty big deal. If you don't think so, that's completely fine, but simply assuming nothing will come of a lawsuit is a bit of an overstep IMO.
By the way, I'm not sure d you're aware of how the windows phone store works, but it's essentially the same as the AppStore in terms of how apps are sold, stored etc. unfortunate windows phone 7 users, who's phones are as little as six with months old (in fact they still sell them) run into this issue, on a lesser scale, again based on the distribution model.
Edit: excuse the typos. I'm posting on my phone.