Quote from Laissez Faire:
Yes, patterns can be objectively defined and traded mechanically, but that does not necessarily translate into a profitable system.
...So, that's the challenge. Consider all relevant factors, understand them, put them together and create a system that's profitable through ever changing market conditions.
Not easy at all.
My two cents.
Correct, there is "objective TA" and such does not imply the trader using such will be profitable. There's also "subjective TA" and such does not imply the trader using such will be profitable.
The determining factor about someone's profitability that's using TA is how that TA is integrated into one's trading plan (e.g. market context, money management, trade management, position size management, capitalization, discipline and other components of the plan).
Yeah, putting the puzzle together is not easy. Yet, the misconception given is that some of these traders with a complete trading plan that took them tons of time & energy developing...
They will then tell other traders (including newbies) that trading is easy when in fact the route to easy trading was very difficult.