In fairness to Kurri and Recchi, they were both top-5 in points three times (Tkachuk was never top-10 as you're addressing), and points are more important than goals. Your point stands with players like McDonald, Mullen, Ciccarelli, etc, though.
I do not disagree with what you however I think at some point when looking at these stats we really do have to look at teammates. While I am not at all disputing Kurri and Recchi greatness nor am I trying to put any player ahead I want to mention a couple of things that show how inferior the players Tkachuk got to play with were.
In the 5 seasons Kurri finished top 10, in 4 of them he had at least 2 other Oilers in the top 10 with him including one season with 3 ahead of him two seasons 2 were ahead of him and one season with one above him and another below him still in top 10. The last year he finished in the top 10 he finished 8th and that was the first year without Gretzky.
Recchi was obviously less extreme but had some good team-mates and same thing with LeClair (who is the main guy that I find odd some have him that much higher).
When I look at only the seasons Tkachuk led his team in scoring you have 5 seasons in which the 2nd place scorer finished 7pts, 26pts, 17pts, 10pts (and he played 10 less games than 2nd), and 6pts behind him. So for the most part during his peak scoring seasons Tkachuk led his team in scoring and at times not even close. And that is for points which is what his weakness is said to be. His goal scoring numbers are even a bigger separation. He led his team in goals 8 seasons and finished ahead of 2nd place on team by 8, 23, 20, 14, 10 (only played 69gm), 5, 3, 10.
I just have to believe if Tkachuk had the benefit of playing with some of the players these other guys did during their peaks his point and goal totals would look different.