Oh but there IS a lock in cost. Trust me.
Trust me, it's not a monetary lock in cost for working professionals. If, for example, Pixelmator becomes 'good enough' then Photoshop users that don't like Adobe's subscription model will dump Photoshop for Pixelmator. No one is going to say "Man, I spent $120 on the annual PS/LR combo last year so I better spend $120 again this year as opposed to buying a perpetual license of Pixelmator for $30." If/when better apps exist then people will leave if they want to. I'm half way through my second year of CC and won't sign up again unless I keep getting gigs that require PPro.
Adobe has to keep the annual subscription costs low enough to keep people signing up year after year but that lower monetary investment also makes it easier for people to leave.
If you're not using the app for a living, then the $600/year subscription "may" hurt a little.
Then those people should buy CS6 from Adobe.com or find CS5.5 or 5.0 for super cheap on eBay or Craigslist. If you are just dabbling or brand new to the software you'll be fine on older versions. I'm not sure why people think brand new, professional level software should be priced so that people who don't use the software to earn money would find it affordable.
Hell, there's a lot of hardware/software I would like to have but it doesn't make financial sense for me to buy it. Is it Autodesk's fault that I find Smoke prohibitively expensive? No, I just wouldn't get enough use out of Smoke to justify the expense.
When I was in college we had Avids to edit on (which was somewhat rare in back then) but when I graduated I couldn't afford the $50,000 or so an entry level system would cost so I spent a few grand and built a PC running Adobe Premiere (the old Premiere) with a Matrox RT2500 I/O and DV accelerator card (yes, this was so long ago that computers could barely handle DV footage). It kinda suck, but it was the best I could do at the time and I used small gigs to cover the costs.
After a couple of years I was really over the PC/Premiere experience so I bought a top of the line Mac tower (Dual 1.0 ghz G4 Quicksliver) and a copy of FCP (FCP, just FCP, was $999). I had to finance all this but I considered it an investment since it I would be learning more marketable software and landing more gigs. As I got more gigs I bought a low end broadcast monitor, a CD/DVD labeler, upgraded software, etc.,. but I didn't buy anything that wouldn't earn it's keep. If I was going to spend $600 upgrading my software then I better have a gig lined up that would pay me at least $600. If I was going to spend a couple grand on a new computer then I knew I needed to line up enough gigs to pay for the new computer. I didn't buy anything that wouldn't pay for itself (I still don't).
TL;DR If you want nicer things earn more money so you can buy nicer things.