Landscape vs Portrait

[Logan]

My grandfather used an HP 15c and I've gotten to know it by using the manual and such. It was surely a fine calculator and a really great size, but I can't get over the landscape design.

So perhaps I'm using it wrong?

I find that often my right thumb is busy pressing numbers and decimal points while my left thumb sits idle.

Then I use the shift keys and various functions on the left side while my right thumb sits idle. I can reach all the way across with either but it is awkward and unnatural (e.g., pi^2 requires four button presses, the first pair is okay with left thumb right thumb, but then the second requires just left thumb or right thumb crossing left thumb).

I find that with portrait mode, everything is centered and I use both thumbs quicker and more efficiently. I can do a shift with left thumb and hit anything on the keyboard with the right. I can enter digits with both thumbs quite quickly.

So what is the appeal of landscape? Is there some trick I'm not doing? Is it just something you get used to?