Isn't the polymer way better than the lacquer?
Not really. Both protect the steel case from corrosion. The polymer is a bit more "slippery" and may chamber and feed better in certain guns (particularly in .223, which has a much less tapered case and more surface area for the case and chamber to "grip" onto each other).
Brazillions of rounds of the lacquered stuff were fired by Russian/Soviet military forces, Russian/Soviet allies/trade partners, revolutionaries, terrorists, freedom fighters, civilians, and others over the years. If the ammo were really that bad, do you think the AK would have it's reputation for extreme reliability?
I've fired 7.62x39mm, .223 Remington, 9mm Luger, and .45 ACP poly and lacquered coated Wolf (none of the new lacquer stuff, only the older stuff) out of numerous firearms. I've fired Barnaul .30-06 lacquered cases out of an M1 Garand and a Remington 700. I can count the number of issues I've experienced while shooting the ammo on one hand (three stovepipes in my Yugo SKS, and one failure-to-eject of a copper-colored steel .380 pistol casing that didn't quite make it out of my Bersa Thunder .380).
The lacquer doesn't come off the casing during firing, and some individuals have heated the lacquered cases with blowtorches to see if the lacquer would melt. It did not.
Lacquered cases aren't a big deal in cartridges and guns that were designed for them (such as AKs and SKSs). They might have more issues than the poly-coated stuff in cartridges and guns not designed for them (such as .223 Rem and ARs), but the poly-coated ones seem to work fine in all guns.
Your mileage may vary.