Personally, I laugh when I hear 10 year old kids say this completely out of context. They obviously do not know the meaning of Internet trolling.
But as for not-10-year-old kids, the phrase has become so mainstream now it means nothing. Same with the word ‘trolling’ itself.
“Oh hey guys, I’m new to this game, so don’t get upset if I do bad!”
[later on; doing bad]
“Sorry guys! That was my fault, I know what to do now though! :) "
“lolumad ur so bad at this dude stop trolling im gonna report you”
I think it has to do with geekiness is now more socially acceptible than ever before. Therefore quoting mematic phrases from the Internet is now a “cool” thing to do. These phrases are showing their faces more commonly in public and over time simply become overused.
As for just being a jerk and pointing out people’s flaws, humans have done this for millenia and on the Internet it doesn’t change.
For the record I just pretty much laugh at anyone who says lolumad.