Wouldn’t plastic or metal be better?
This is a joke right.
go buy a yomega star kendama haha…but seriously wood plays better…just put some glue on the tip and it lasts longer =]
A metals tip would wreck the wood ball.
Oh… What about rubber? And a plastic ball?
Wood has been working fine for everyone for hundreds of years…
Wood also worked fine for yoyos for hundreds of years (and still does). I don’t see why the idea of investigating alternate materials (and questioning the status quo) is getting shot down so hard!
However if you want a plastic or metal kendama (and I’m talking ALL metal or plastic, including the ball), you can look around for one made by KendAlex, since I believe he is the only one who makes them or at least use to. He actually has a profile on YoYoExpert too, I believe his username is Supernog73. Pm if you like. 
I don’t know why no one is making them with tips that screw into threaded inserts in the body. The design could be worked out to preserve the balance, and you could just buy replacement tips.
I don’t really care though. I am not into kendama.
There use to be something like that I think, believe it was called “Yumu” or something like that, don’t know if they still sell them, but I do know they still sell replacement tips. However these are different because you don’t replace the spike but rather you add spikes to the cups. 
However I think the real reason no ones really does it is because then the kendama market would go down. This is because usually when people buy a new kendama it is because the spike gets dull and so the only way to get a better spike is to buy a new one. Well if people could just replace the tip that would be fine…for the consumer. However for the seller, I’m sure they would rather sell a whole new kendama than just a replacement part and thus there is more profit made from not making kendamas with replaceable tips rather than making kendamas with replacement tips, but still I could be wrong and it could be just because no ones thought of it. 
I’m pretty sure 3YO3 is working on acrylic Kendamas
The whole kendama or just the tama?
Also an Aluminum ken.
Oh so they are revamping what KendAlex did? That’s cool, never got to own one of KendAlex’s stuff, but hopefully I’ll be able to get one of the 3Yo3’s kendamas. 
I think there are several reasons. For a lot of people the simple, traditional wood ken is a big part of the appeal. Also, in North America it’s not a big deal, but in Europe and Asia and the UK, only certain kendamas are legal to use in competition. It’s kind of nice that you can’t really spend much more than $20 on one. It levels the playing field a little. Anything new or different can’t be used. Plus like gorillaz922 said, if you coat the tip with superglue, it will last much longer. Some of you guys have got suitcases full of nice metal yoyos. Is the point wearing out really that big a deal? Sweets sells replacement kens. That said, one of the acrylic ones would be nice to have. With one of the aluminum ones I’d probably just end up with a concussion…
Hello Folks,
just to hook in on the question,
most kedamas are made of wood because that is not to heavy and with normal use after a few years experience a single kendama can get along for more years,
(for example i had several mugens and these were 3 years old and still in good shape, 3 months ago i sold them to a other player to let hem play mugen too, and he still rocking it)
i did glue tipped the spike for longer lasting,
if you making kendamas with a spike you can switch after it gets dull the ken will be not as strong as it is made out of one piece, and making a piece of metal in the tip is making the ken out of balace
and yes i also make Aluminium kendamas and full Delrin plastics, my products are perfectly balanced and accepted by JKA Kendama players (japanese Kendama association)
just because you can do all the tricks with it that you want.
both kendamas are Hard skilltoys because lighthouse trick for example is very hard to land, you need sort of a skill level to land them solid,
(once in a while i do pre-orders for People that like to add one to the collection, i don’t have a website i only deal by trust on facebook and email)
if you want more details please send me a PM