My take is that yes there is playful tickling, erotic tickling, sensual tickling, torturous tickling and even playfully, erotic, sensually torturous tickling 😉
Basically whatever your cup of tea is, drink it.
I love playful ticklings for just the fun of it...to get the laughs out, to have fun, to cause a reaction.
I love erotic tickling for the closeness of it, to the the moans and hisses and laughter out, to have the lee want MORE Of what I am doing...
Now I will admit that occationally, I may get "exited" when playfully tickling, an adult(lets be clear)but I certainly don't act on it, if the whole point is just playful fun.
I can see where your friend is coming from but he is off base...now HE may not be able to seperate the two but there are people that can and do.
To each their own basically.