As an amateur, i think a guru is anyone who trades for a living.
I dont think this individual, or guru, could transfer "that" to someone else
because it is razor thin , as in "one thing wrong" and it doesnt work.
Mentoring might be extremely frustrating and unsuccessful.
This implies a high degree of individuality. I am certain, as i can be, that
a canned method cannot work for the masses. But we all know that.
And if there is any doubt of that for newer folks then it would be wise not to waffle
on this, pick a side, and dont waste too much time.
IMO.
Guru is a teacher in Sanskrit. Guru has a doctrine, and followers to whom he tries to transmit his wisdom.
Anyone who trades for a living can be guru, in theory, but why, what for?
By the time a person reach that level he is usually beyond the age, when you want everybody to stand up when you entering the room (or forum)
Money ? Traders usually quite rich, may be not f@king reach but very close to that...

, (and remember you can not find their names in Forbes and they do not give interviews on CNBC)
So real traders that still can trade - do not teach.
Now about the subject.
I personally do not believe that somebody who could not not make it himself can teach trading. So when I hear someone selling trading courses or trading methods, I know its a bullshit.
I have no problem when peoples teach or sell anything else related (or possibly can be related) to trading.
Teaching math - no problem, programming lessons -ok, theory of any kind of analysis - sure, anything... just do not say you teach how to trade which is how to make money!
People, of any occupation may sell they knowledge as a product because otherwise they will not make money. Not the trader.
Trader is the only occupation when you make final goal off all peoples efforts - Money !
Now who is the trader in my definition.
Very simple - trader is anyone who trades for a living using only his own money (margin is ok).
That's it... all those parrots form the Wall Street, that called traders, they are just executioners of orders and will not survive a day, trading on their own... (that's why when fired their become waiters.. and that's what their really are.. waiters)
Everybody else, those suckers that make mere 10 % a year, and think that this a limit of everybody else's dreams and abilities, may be money managers, financial consultants, even fund managers, they all are not traders. They are not making money on the market, their making money near the market - serving clients....
So bottom line - there are no gurus, because gurus do not talk, do not teach, do not make statements: "Buy (or short) XYZ !"