Because the sound files are directly ripped from VF5FS, respectively. The only thing they altered was the character models and the effects of some movesets in order to adapt to DOA5's gameplay system.
Free Step Dodge
Awesmic
Force_of_Nature
Tell that to SEGA.
Komatose
Wow that is so annoying. We have those clean-sounding voices then we have those obvious VF-sounding ones like Sarah and Pie. Ugh. And Jackey...
ninemil
That's my biggest gripe with their inclusion. I like that their move set is out of the DoA box, but their presence is so disruptive when the stupid sound effects kick in. It drags you out of your zone waaay too much.