Why do top-tier players buy Berserker's Greaves?

There seems to be a general consensus that Berserker Greaves are bad items and should only be purchased when the other team has little or no CC. However, I've seen several guides by top-tier players recommending Berserker Greaves on various champions like Kayle (Reginald), Shaco (Reginald), and Tristana (Dan Dinh), and I swear I've seen it for Warwick as well. Is there any reason they'd recommend Berserker Greaves (other than trolling)?

I'd assume some characters can stay out of the line of fire, so it's a better purchase than Merc Treads. It's also one of the cheaper Boots 2 options, costing only 920g vs. 1100g for Sorc Boots and 1200g for Merc Treads.