There's no reason not to; some champions would rather have the on-hit effect of Sheen than the Luden's passive.
It works great for tanks because it solves their mana issues and gives them an on-hit that a handful of them can use well 
because they're encouraged to auto-attack. They won't get the same value out of Runic Echo and I find it really frustrating that Riot doesn't allow two items with different demographics to exist.
SaltyKracka2 votesTanks didn't build Runeglaive in the first place.
Big Lincoln2 votesI build it
and it works, and until cinderhulk stops being terrible I'll keep building it while it's still here
S H A Y C 02 votesis cinderhulk terrible?
xSleepy4 votescinderhulk is fine rn... no idea what he's talking about
Big Lincoln1 voteswhy would i build it? it offers nothing of value other than health, which I'll have plenty of with other items
runeglaive gives me immensely better clears, better sustain, CDR, and converts my AA into magic damage. that's a lot better than some health and a sub-par sunfire cape which requires a lot of items to have a noticeable effect with the health scaling
S H A Y C 02 votesthe difference is whether you go full tank or off tank / anti-carry. If you are building runeglaive or any damage, you arent going full tank. so at minimum you are shooting for an off-tank. the difference is whether or not you breach 4k health or not with your rediculously tanky build on your cc machine. Thats what cinderhulk is for. its the item that finalizes all your tank items...which should have hp in them for the most part with 
being the two most popular exceptions.
Its not meant to be damage...just help you get through the jungle, and then be a titan of hp late game.
Big Lincoln2 votes
- full tank gives you everything you need, lol. 
/
/ 
is a great build to run with
Cinderhulk is also complete ass on tank Ekko because he has huge mana issues, and this item is not going to do him any favors unless he invests in AP
Earl Eulrich2 votesruneglaive makes your clear and your ganks a lot stronger on cc/combo-tanks like e.g. naut, maokai, seju that can only assault you for so long - cinderhulk is a legit choice for the likes of mumu or trundle that will just go turretdive with it...depends on your setup if you want the early spike or a little more tankiness right now. I wouldn´t say Cinderhulk is terrible...but it´s not really satisfying either.
Paroe1 votes[{quoted}](name=ToiletteOfDoom ,realm=NA,application-id=3ErqAdtq,discussion-id=u4mXZQ7E,comment-id=000000000000,timestamp=2015-12-08T21:10:47.334+0000)
is cinderhulk terrible?
Its worse than getting an actual sunfire cape. Much less damage.
Earl Eulrich1 votesi absolutly agree...what´s so bad about offering more choices to the player? like the OP said, it works great on tanks that have lots of mana-issues atm - but don´t necessartily want the AP (or the tank-thing), it´s also still very solid on some off-build-junglers like irelia, fizz or diana. Why would it be bad to have an actual choice that impacts the playstyle rather then to just force everyone to build the same item every game?
(also, donßt forget to nerf elise if you get that new iitem to live).
The Bearded Bard1 votesAre they getting rid of runeglaive?
Sona Ping1 votesMost likely.
It did need something now that all machetes grant 150% mana regeneration which cut into runeglaive's territory.
Weathered1 votes
Big Lincoln1 votescrazy idea
keep both
euJHINius1 votesI said this on another post:
Thats kinda the reason why we don't have Ranger's Trailblazer. Rangers was supposed to help people who cant clear well, but was also abused by those who already cleared very well. Runeglaive is designed to be an AP item for AP Junglers. If people build it just for their mana problems to be covered, it doesn't help its intended niche.
Also it didn't really help out any actual AP Junglers except those that had built-in on-hit effects like Ekko, Diana, or Elise.