Not so sure cultural dictates is in order with spelling. Prior to internet I always spelled humour this way, in fact several other words not on the tip of my lips right now, so I am not so sure that is always true.
Now now, if you were at a table having a cuppa with these fine people and they laughed would you find that offensive? LOL is just that, don't you chuckle or laugh when you post or read posts? I do all the time! ahahaha.....okay, you can bonk my post, because in truth no one can steal away my joy. Not that you want to do that, however, the comment about lol is just hogwash. and now I laugh or dare I say "lol"? So you are not a part of a culture that likes to laugh/tease/fun around?
I was just pondering the heavy in this world this morning and concluded there is not enough light heartedness.