I think many guests, especially Japanese, would find the room just fine. I agree with you that drabness is common in hotel room interiors in Japan, but the entry of many upper-end and luxury Western hotels over the years has caused many Japanese hotel chains to up their game and offer nicer and more stylishly designed rooms. IMO, this is clearly a growing trend in Japan and I would expect it in a Marriott hotel of the Prince Tower's caliber, an Autograph Collection Hotel after all. But my main point is that the lobbies and public facilities (restaurants, club lounges, etc.) were all attractively presented, mostly in an appealing modern Japanese style, but for some reason the rooms were not. This was an inconsistency that stood out to me, especially considering the price point and category of this hotel