Maybe I can clear some things up.
Reason Apple has given up optical discs: people lose them and they are EXPENSIVE to manufacture and distribute compared to digital downloads. You want to go back to paying $100+ for every OS release, you go right ahead ... I, on the other hand, prefer the $20 pricetag.
There is a nearly-foolproof system built into Mountain Lion that protects your purchase of ML whether you just want to reinstall for some strange reason or you've lost the HD (it's called Internet Recovery). I cannot even imagine how many landfills filled with unused silver discs this saves every year ...
I find it kind of amusing that people who get their music, videos and third-party software from digital downloads on a routine basis -- and have done so for well nigh on a decade -- are suddenly very concerned that Apple has done the same thing. If you want a "physical" copy of your OS, hey that's a great idea. Make one! If you're concerned about protecting your purchases, back them up -- but even if you don't, the App Store remembers what you bought and will let you re-download for free. Not seeing a problem with this compared to "I can't find my discs" which is often code for "I, um, never had the discs if you get my drift."
I don't know if you've noticed, but the overall price of consumer software has come WAY WAY DOWN over the last few years, entirely due to to reduced costs brought about digital ecosystems.
As for renting software (see: MS Office 365 and Adobe CC) -- this is EXACTLY how you do digital software INCORRECTLY. That said, your subscription Adobe software still resides on your disk exactly as it always did -- it just now checks to make sure you have a license to use it that's still in good standing. Other companies (cough MS cough Quark cough) have been doing this for many years. The part that kinda sucks is this attitude that we all need more monthly bills, and the assumption that everyone who uses Photoshop (for example) use it all the time, every month.
That's okay, Adobe will learn VERY QUICKLY that this is not the usage pattern for a significant portion of their base. For some people, $50/month for the whole Creative Suite and automatic updates, support etc is a perfectly OK deal since they were paying to be up-to-date anyway, and this costs about the same but with some benefits. For others, the occasional $20 spent to "rent" Photoshop for a month works out okay too.
For many users, however, neither of those options seems attractive. I suspect both MS and Adobe will have to eventually retreat back to offering a version that can be used entirely offline.*
*Both Office 365 and Adobe CC can be used offline as well -- in the case of Adobe CC, for up to six months at a time. There's this incorrect perception that your app and work is in the cloud that simply isn't true. These aren't "cloud apps" any more than Pages is a "cloud app." It's more accurate to say they are "cloud licensed" or in the case of Apple, "apps with a cloud option."
So what will happen when Adobe stops supporting CS6 (contrary to the above, they still sell and support it)? One of two things: Adobe will get an earful and go back to offering "perpetual" licensing in some circumstances, or other companies (cough Acorn cough Pixelmator) will see that lost business opportunity and do something about it. Nature abhors and all that.
Change is always annoying and disruptive, but the overall idea is that the new way has advantages over the old way. I personally think the advantages of cloud storage, cloud sync and cloud licensing are pretty obvious, but that's because I have a good understanding of where this is a good idea (iTunes) and where it isn't IMO (Adobe CC).
Lastly: as mentioned above, if you're on Lion or bought Lion, you have the option of re-downloading Lion. It's just not available to people who didn't do those things.