How come Dead Man's Plate can be a tank item that gives movement speed but

Gonna be honest, my mind subconsciously filled in the rest of the question with "But Graves can't have a cigar?"

Two reasons.

1. Movement speed wasn't the true problem with Force of Nature.
2. It's been years. You can't apply ideas from Riot's current philosophy to old items and expect to make a sound argument out of it.

Because 76 magic resist.

But we do....X

They didn't like FoN's stat combination, and efficiency as a single slot MR item after you had your Warmogs, Atma's, Randuins, Merc Treads, or whatever high health build your tank/bruiser used.

They instead chose to go with items that are more early/mid-game friendly and can be rushed by tanks.

You don't need any other item to make great use of Deadman's Plate.

The only item remaining with that stigma is Warmog's -- and it's pretty much a dead item currently.

To put it explicitly. Force of Nature was making mages irrelevant at the time.

Having a single item grant 70+ MR and 1.75% HP per 5 was making it pretty much impossible for them to be relevant, because Liandry's Torment wasn't a thing, MPen was scaled backwards and their items were more expensive.

To make matters even worse, it was actually massively cost-inefficient. It was worth less than 70% of the gold spent on the stats, yet it was still so strong that it effectively negated an archetype of champions.

There's no reason to bring it back, really. MR itemization has been improved and expanded, and there isn't really a need for an item that provides just MR, HP5 and MS. If Riot ever brings back Force of Nature, it's not going to be the same item it was. It'll be like Aegis of the Legion's multitude of changes.

DMP is more of a bruiser item than a tank item?