Malone was a dominant scorer, but he was not much more dominant than Frank Nighbor, and Malone was pretty useless in all areas but scoring goals.
He was more dominant that Nighbor, yes. Nighbor had one big offensive season in 16/17, while Malone had many: 12/13, 14/15, 15/16, 16/17, 17/18, 18/19 and 19/20.
Nighbor is pretty clearly the better overall player of the two, but he was mostly "only" very good offensively and dominant defensively, and "not quite as good as Frank Nighbor" is hardly a black spot on your record. And then there's the idea that a player who "only" scores goals is somehow lacking, as if scoring goals doesn't help your team win.
But when I mention "stats without context," I am talking about when people list Malone's 1918 season as "perhaps the best goal scoring season of all time" since he scored 44 goals in 20 games.
That's what I though you meant, and it is a fallacious claim, but you're downgrading it too much. "Not the best goal-scoring season of all time" describes many outstanding player-seasons, including that one. I'd say 17/18 was Malone's second-best season, to 12/13.
2) Malone scores 23 of his 44 goals in 7 games against an Ottawa team that was missing Frank Nighbor.
Then's there's 19/20, with Ottawa having a fully healthy Nighbor, and Malone having almost no help from his teammates when he scored 39 goals, 50% more than Nighbor. Newsy Lalonde scored nearly as many as Malone, but again "barely ourscored Newsy Lalonde" is hardly an insult.
Malone was ranked a top 50 player of all time by HOH and THN. Knowing what I know now, that's unjustifiable.
I could see a top-50 argument for him maybe. It's not like there's really much difference between a top-50 player and say, a top-80 player when you're discussing all-time.
I've seen people call Hainsworth a top 10 goalie of all time, but Charlie Gardiner and Roy Worters were almost universally considered better goalies by contemporaries. Even in Hainsworth's record breaking 1929, Worters was selected "1st Team All Star" on the unofficial teams voted on by the 10 NHL managers. We have full voting results for the 1928 team, when Hainsworth also led the NHL in GAA, and Worters dominated the voting. Hainsworth was selected to the second team, but he was barely ahead of Alec Connell.
I've found in reading all these old game reports etc. that goalies on bad teams tend to get a lot of praise, presumably because they had so much work to do, so much opportunity to make big saves because their teammates were allowing a lot of good shots. They got a lot of notice, whereas a quietly effective netminder would not.
Which is not to say anything against Worters or Gardiner. But you can't focus too much on any one source of information, I'd suggest.
There's an argument to be made for Hainsworth being rated highly. I certainly wouldn't say top 10, and again maybe because you've heard some people (whoever they are) say top 10, you see him as overrated. From my perspective, in general he's likely to be underrated by most people because he played before WW2.