Indeed, OCSouthpaw, it comes down to what matters more--as all such decisions do! To this client, what mattered more was not seeing a paper towel holder sitting out on the counter. Their concern has become even more important as the walls have come down around the kitchen. More and more, my clients opt for less visual clutter, not more.

That said, to you, it's a waste of cupboard space. However, what's not apparent in this photo is that my wall cabinet depths are made to hold 25% more than the industry's 12"-deep standard. This standard was not people/user-driven. It was set by optimizing a sheet of plywood. This was driven by the lessons in standardization we learned during WW2.

Now, two of the largest European manufacturers make their wall cabinets 15"-deep (38 cm). I've been doing that for over 30 years. They--and my clients--have found that this is a far more useful depth. Of course, their base cabinets (and mine) are deeper, as well, offering 27"- or 30"-deep counters.

With this depth, a PT holder in the rear corner of a cabinet (the least used portion) takes less than half the depth of the cabinet. In the 30+ years I've offered this option, the loss of storage has never come up.