How To RPG: Lore is the Spice That Makes Campaigns Tasty

There's nothing wrong with your setting having some history to it. The issue comes when you got storygame wankers wanting to vent their writing/acting frustrations through a campaign, instead of doing the right thing and actually working on their writing/acting skills so they can actually satisfy those desires properly.

The trick is to put that history where the game is, and then to make it a treasure of its own, one where acquiring such actually makes acquiring the stuff most gamers are after--power and wealth--easier and faster. For my own D&D campaign, I make it clear that you're going to find that stuff only in dungeons and similar adventure sites. You want to know why the lizardmen have a mythology surrounding an exodus from a mother planet. Why? Because you'll never get that Staff of the Archmage without it.

This isn't an excuse to engage in pixel-bitching bullshit. You put the lore into the location that fits the site's original purpose. A temple, being a place of worship, has religious and mythological lore associated with it. Instead of reducing this to a die roll, as too many RPG systems do, putting it in the rooms' descriptions is the way to go; let players take notes, have their character sketch stuff, and run their curious asses to a sage in town to handle the gruntwork of research while they pursue other active leads.

History, mythology, architecture- all of this is the lore that makes campaigns feel alive in ways that mechanics can't handle, and with that in mind you can make the lore immediately and directly relevant without making it boring bitchwork players have to handle to get their gold, wands, and +1 swords. Put practical information into the lore and watch players embrace it, then get enchanted by it.

Summarized: Lore exists to facilitate gameplay in the campaign, not the other way around. It's grease for the gears, spice for the meat, and not the point of the exercise. Keep that in mind, and you will prosper greatly by using it. Too much and Gordon Ramsey's gamer cousin will scream at you while beating you about the shoulders with his dice bag. You don't want that.