I have a 29 yr old Takamine 12 that came with no pickguard. I'm also a flatpicker and that particular Tak was my No:1 for 27 years in a Celtic Folk band. When I bought it, the dealer offered to put a "clear" guard on it, but it was a satin finish and I said no, thank you.
It's got some road wear and a couple of dings, but there are no scratches worthy of note in the area below the strings.
That said, it also hasn't been "satin" finish since about a year after I bought it. Oh well.
I guess my "style" (light picks, light strumming) seems to be okay without a guard, so I have no plans to put one on the much newer T5z that's my current mainstay.