It seems simply wrong to keep the best goal-scorer ever out of top10 players all-time. It is like having no goalies in top10-top15 players all-time or having no defensemen there other than Orr.
On the other hand, having the best goal-scorer ever as #5 player all-time seems an obvious choice for anyone who values goal-scoring highly.
I get what you're saying -- the point of hockey games is to outscore the opposition; therefore, the guy who was best at scoring goals has to be top-5. To the lay fan, that might seem logical, but in reality it doesn't work like that.
To start with, I personally think (and you may disagree) that the rarest and most valuable offensive hockey players are the ones who are elite -- or at least very, very good -- at
both scoring goals and at setting them up (play-making, if you like). Ovechkin in his heyday had a few top-10 assists seasons, which is good, and he had his one and only scoring title in 2008. He clearly is/was a competent and skilled passer/playmaker... but he has never been elite at it, and has only rarely been, say, top ten or fifteen in the play-making category. Anyway, I would personally (and you may disagree) rank someone like Jaromir Jagr (or Jean Beliveau) ahead of Ovechkin in terms of offensive ability and overall impact, largely because Jagr was better at both scoring goals and setting them up. 5 scoring titles is far more impressive than 1, and while Ovechkin's goals-titles are otherworldly (in fact, the most ever in the NHL), I simply don't find goals totals to be nearly as impressive as point totals, especially among the players who are good at both scoring and setting up (less so the Joe Thornton / Adam Oates type, who is not impressive as a goal-scorer). Bobby Hull had one fewer (so far) NHL goals' title than Ovechkin (plus another in the WHA), but he also had three scoring titles to Ovechkin's one, and a bunch of top-6 assists finishes.
Next, there is obviously consideration of defensive play and goaltenders. (Ovechkin doesn't get any notable points for these, obviously!) We've got D-men who won 7 or 8 Norris trophies (Harvey, Lidstrom) in addition to Bobby Orr. Then, there are the greatest goaltenders ever, such as Plante, Hall, Roy, and Hasek.
I like Ovechkin very much, of course (who doesn't?), but from watching him, I don't get the sense of him driving his line, or controlling the play on the ice as much as some of the greatest players ever.
That said, if he's a near-consensus top-3 all time goal scorer (which I think he is by now), he still has to rank very high in the all-time players' lists, of course. I personally would rank him somewhere around 15th or so, but it's an inexact science. In any case, I cannot really see any argument for him in fifth-place. That just seems way too high, regardless of how many goals he ends up with.