In my experience, in a well run game, the DM loves his lore... and the players love it almost as much, overall, but there will be a spectrum. If the lore of a world is going to be intriguing, captivating and exciting, the DM must be in love with it. They have to feel like an artist making the work they'd be proud to show. Players usually can't match that interest or passion ... overall. However, they can become very tied up in the portion of the lore that centers around their PCs. And you can have a spectrum of interest from your players in any campaign.
Take Vox Machina as an example. Matt loves crafting his world - and worked really hard to make a complex and interesting world for his playeras to experience. Ashley, bless her heart, followed along but never really got into much of the lore outside of her relationship to Grog and her Goddess. Meanwhile, Taliesin worked with Matt to etch his character's backstory into a fundamental element of the campaign world that impacted Campaign 1, 2 and 3. Travis played a dumb character so that he didn't have to know anything about the game or the setting ... but he took a huge interest in his tribe and knew when to shine in the story that was about his character. As the campaign moved forward, Liam dug deeper and deeper into the lore and explored elements that had not been part of his origin but that Matt had exposed - like the Raven Queen. Sam mostly just 'followed the bouncing ball' until after Scanlan returned ... but in the tail end you could see him paying attention in new ways and appreciating his bard all the more - and I think it came when he realized that there was going to be a Campaign 2 soon, and what they did to close Campaign 1 would impact that new Campaign.
I talk with people that DMed for me in the 80s and early 90s and we tell war stories about the campaigns they ran for me - and they share with me how those events still impact their campaign setting today. My campaign setting has been rebooted a few times now when I've brought new players to it ... and each time I steal elements from the prior campaign run throughs ... and just this last weekend I have a former player a recap of 20 sessions of the new group going through a section of the campaign that takes places somewhere his group never explored.
Note: I read this as a question of whether DMs care more about the lore than the players care about the lore. If the question was: Do DMs care more about the Lore, or the people playing the game ... The DM has to care about the players more. I've reworked entire campaigns because a player went through something that made one of the storylines take on a different meaning for them, and I refused to expose them to it and put them in harm's way. Every DM should be willing to make those changes.