What happened to corrosive being good against flesh as well as corrosive?

I remember in Borderlands 2, they mention that corrosive is good against armour & flesh, was this an actual thing in the game, or was it just a gag to the fact it’s acid and it would definitely melt your skin as well like in real life. Timmy also mentions it in Handsome Jackpot so I’m honestly just curious.