I can confirm about nettings, can't find them neither elsewhere. But ttsko and gorka uniforms are spawning. I found them for sure on prison island (full of police and military clothes) and, if I remember correctly, in the military camp of NWAF.

Yesterday we found 2 nettings on the coast.

Netting spawns, found 6 yesterday on coast and prison island.

Netting is spawning on the south coast of Cherno, however it does not spawn at the berezhki fishing village; I was lucky and found 10 netting on the coast on one server.

If this was an issue, it is not anymore. I've found a hundred nets on dozens of servers all at boats over the last two weeks. Perhaps this was fixed in .57 or the OP simply had a bad run of looting.