Dowels get a bad rep mostly because people that use them are usually new archers that don't have much experience in making arrows or much understanding about wood. They do almost everything wrong, because of their inexperience, and then blame the dowel as being bad.
Well it's not quite so simple as that. A dowel is a piece of wood. Just like a board. Boards were once thought to be some how mystically different then staves cut from trees. Once people figured out that a board is a piece of wood like a stave and it's the cut of the grain that really matters, board bows became very popular and effective. Some true masters of the craft even prefer board bows. I like them both personally.
With dowels you may have to go through 100 to find 5-10 that have good grain. Then you go to all the other hardware stores and do the same. You end up with 50-60 shafts for dirt cheap. Then you spine them. Slightly high spines can be sanded in the middle to get them within range without effecting looks or shooting ability. Nocks can be cut or glued slightly at an angle to the normal perpendicular to the grain rule to get them to flex a bit more and thus spine less. I've seen absolutely no difference in durability from doing this.
There are a lot of tricks to getting them to spine right and none of them are especially hard. Wooden bow and arrow making is not simply gluing store bought pieces together it's about understanding the properties of wood and lots of hands on experience...
All that matters in the end is your arrows are uniform and consistent in every way and tuned correctly to your bow. And that can be accomplished with dowels believe it or not, or wood arrows in general. One just needs to put the time in to figure out all the tricks. For what it's worth though, I rarely use dowels, not because it's not possible but because their are easier ways to go about making good wooden arrows.
I'm not comparing wood to aluminum or carbon here because these materials produce better shafts but people have been making very long and accurate shots with wood arrows for a long time. They are definitely still worth using.