I agree with some of what you say, but not all of it. Manufacturer recommendation of synthetic oil is a tricky subject. For more and more luxury cars, synthetic is being recommended (or even required) and I don't just mean super-cars. A luxury car buyer is not going to be put off by the extra cost of synthetic oil and there is no question about its benefits.
For mainstream cars, there has been a reluctance by manufacturers to recommend synthetic because they know that in a sales situation, competitors are going to play up the extra cost of synthetic oil change if they require it. However, some manufacturers like Toyota and Honda have now taken the plunge and require synthetic on most of their cars. I say "require," but it a bit more complicated than that. In order to avoid the stigma of trying to sell a car that costs more to maintain than the competition, they just say you must use 0W-20 motor oil. The trick is that there is no conventional 0W-20 motor oil, only synthetic.
Hyundai has traditionally appealed to very cost conscious auto buyers, those who could not afford the equivalent Toyota or Honda (yes, that is changing), so they have not made the leap to require synthetic yet. But if you keep you car for awhile, there is no question that synthetic motor is better for your engine than conventional oil. No question at all. Many Hyundai dealers in my area use synthetic blend oil (half conventional and half synthetic) for standard oil changes (unless customer upgrades to synthetic oil). As car engines move to Direct Injection and Turbo, the use of synthetic is even more important.
Like you say, the cost of synthetics at Walmart is a nit compared to conventional oil. Unfortunately, many service organizations charge outrageous prices for a synthetic oil change. I am fortunate in that I can do my own oil changes, not just for the price savings, but to also make sure it gets done right.
