I guess it's okay to go off on our little tangents since LionSight already gave an actual reply to the OP...
Opticians must have at least a HS diploma or equivalent in order to sit for the certification exam. However, only some 22 odd states require their opticians to be certified in order to work. Keep in mind many places will employ people who are not opticians, but who will still work with dispensing/adjustments and the like. They are either just trained sales associates, or they are working on becoming opticians (look at the name tag!). Therefore, some of these people might indeed be trained high schoolers, but I can't say I've seen any myself. I know for LC, as long as there is at least one ABO certified optician on the floor at all times, this is okay.
Of the certified opticians, I have seen them range from complete idiots to intelligent (like any other profession), and from complete newbies to ABO/NCLE Masters. Even the most knowledgeable and educated of the bunch, whom I greatly respect, will not even come close to what an OD can do. Their knowledge and expertise lies mainly with dispensing (surprise, surprise). They take the rx you got from your OD/OMD, consult their vast knowledge of lenses, factor in your needs/history, and fit you the best possible eyewear they can offer. They do nothing "medical." The only ground they can possibly "compete" on is refraction, and even that one is heavily debated (not gonna go there).
There are literally thousands of lens out there, and the technology is being updated constantly. I believe we are now in the 4th generation of progressive lenses (and each generation is defined mathematically, not by what is latest). I will eat my sock if you can find me a commercial chain location that offers any from the 4th generation (Ipseo, ID, Definity, Individual, etc). From my experience, you are lucky if they offer anything in the 3rd (Comfort, Physio 360, etc). Like KHE said, there's nothing wrong with lenses like Ovations, except that it is close to two decades old (2nd gen, I think). When we call them "crappy" we just mean "freaking old technology," not shoddy production. Just like there is nothing wrong with a 1984 Honda Accord (in working order). It's just, well, there's newer and better technology out there--from Honda as well. So we aren't really insulting Essilor by saying their lenses are old, anymore than if we told Honda their '84 Accords are old.
And face it, the only people who are content with old tech have either decided the upgrade was not worth it, or they do not know of anything better.
As for adjustments and repairs, most chains either don't do it at all, or just replace screws, nosepads, and sometimes temple pieces. They certainly don't solder. Anything more than that is purely on the initiative of the person who is helping you. I, and others, have gone above and beyond for customers who really want to save their frames. I've done frankenstein fixes, bent back frames beyond hope, cut and filed custom screws, made make-shift Locktite, and other Macgyver-worthy repairs. I didn't care whether they were our customers or not. They came to me for help, and I was glad to do what I could and I kinda enjoyed the challenge
. But I assure you most people thought it was a waste of effort.