> unregulated marketThere is no such thing as an unregulated market. The only meaningful difference is between a free market--a market that is regulated solely by the voluntary choices of market participants--and a non-free market--which is at least to some degree also regulated by rules dictated and enforced by entities who are not market participants (the most common such entities, of course, being governments). Both types of markets are regulated; they're just regulated by different mechanisms.
> will always promote marketing over quality
No, a market in which consumers are either unable to perceive quality, or are unwilling to take the time to do so (possibly for rational reasons such as the lack of time or the product being so cheap that it's not worth the effort) will always promote marketing over quality.
But that doesn't mean this is a "problem" that either needs to be or can be fixed by outside regulation. It can't be fixed by outside regulation because outside regulation makes the problem worse, not better; it makes consumers think their interests are being protected, when in fact regulatory capture means all that is really happening is that the biggest players are getting further entrenched because the cost of regulatory compliance shuts out potential competitors.
It doesn't need to be fixed because consumers have the choice of what to buy or not to buy, and if they either can't or won't (again, possibly for rational reasons) take the time to choose based on quality, either they don't buy at all or they choose based on something else, and take the consequences. That's what not taking the time to perceive quality means: you choose to be at the mercy of whatever marketing or other information you do use to determine what to buy (or whether to buy), however unreliable it is.
> no regulation
More precisely, absence of outside regulation from entities like governments that are not market participants. See above.
> means leaving sheep alone with wolves
No, it means consumers make the choice of whether or not to be sheep, and take the consequences. Which is the only way to actually regulate a market and have the regulation actually improve anything. The wolves can't prey on consumers who refuse to be sheep, and that choice is up to the consumer.