I think the definitions are simply wrong.
Talent is the genetic (and nurtured) predisposition toward something.
Being great at something - often conversationally referred to as "talent" - is the combination of predisposition and practice. 10 000 hours of practice is probably not far off mark for any given field, physical or mental.
While the middle of the talent curve for any given field can somewhat make up for predisposition variance with working harder, it is not a good value proposition for those at the lower end of the curve. It is often a waste of time to slog at something you are naturally geared for when the alternate is to work on something you are better suited for.
Passion, drive, curiosity, ambition and mental fortitude also highly variable among people. The "you could do it if you only made an effort"-sentiments really irritate me, even though they usually spring from the inability to understand different minds rather than any malice or sense of superiority.
Virtually everyone has a few talents, and the question is mostly of opportunity to discover them (which does not exist for everyone, even in wealthy societies), "passion" for it - which could less romantically simply be described as the perseverance to work at it through the highs and lows.
In other words, humbug.