Yes there were some recoil spring issues with the early Gen.4 9mm pistols. This was caused by GLOCK attempting to use the same spring in both the 9mm and .40 S&W guns as a cost saving move. The recoil spring for the .40 was too strong for the 9mm especially if inexpensive(cheap) or week ammo was used. They have since replaced the springs with an appropriate to the caliber spring and this,by most all accounts, has resolved the issue. The hype to which you are referring is perpetuated primarily by the bashers you referred to in your OP.
PS: I have both Gen.3 and Gen.4 in both .40 and 9mm and have not experienced any of these issues with just over 9000 rounds downrange between the pistols. 4728 rounds now fired through my Gen.4 G22.as of last Tuesday.
If I were to buy a used 17/19 gen 4, how would I know if it still had the "older" stronger spring?