This is a good question. I have many performance center revolvers with that hammer. I've even hacksawed a few off. And I don't know the reason they went with that type of hammer.
If im allowed to take a guess. I'd say with a hammer like that, it might be easier to holster as a big bulky target hammer might jab you in some parts- depending on the holster and method of use, of course. Or may print through your clothes more with a wider hammer.
A smaller more shaped like in a V may be better.
Just a guess. Curious what other forum members might think.