I'm aware of the history and nexus of the R nineT name. However the bike is not an R90T (presumable pronounced R ninety T).
Totally aware that branding is subjective and personal. My personal opinion is that a bit of company branding when done tastefully is acceptable. Things like a Rizoma logo or 'made in Italy' thrown on a low key area of a well made part is great. Take pride in the craftsmanship and brand but don't overpower the part. In this case my objection is not with the branding, as a DK Design logo wouldn't be offensive generally. What I take offense to is creating an entirely new logo and name for the motorcycle that it is going on. Again I'll refer to Rizoma, but you don't see them making up their own proprietary logo for the each model of motorcycle they support in addition to their own brand logo. Your defense of the logo is that it looks tasteful when combined with other products from the same company with the same logo on it to create a complete look.
Now to get back to DK Designs, I think their stuff looks well made. Some of it is clearly a reproduction of existing items, like copies of the Rizoma Eccentrico mirrors or Rizoma Low Headlight Fairing or SideArm Rear Fender. Others are original and quite nice like the fork mounts for accessory lights. I also like their cylinder protectors made to look like the expensive cylinder heads from BMW. I've had their headlight sitting on a bookmark for ages looking for the cash and an excuse to buy it for myself.