Antenna on mast performs worse?

[jaymot]

This has been discussed here:

PCB stripline antenna, strange design

If you think about local field strength and how an electromagnetic wave interacts with a dipole, it doesn’t matter if the dipole is a flat plate and which angle that plate is at. Well … within reason. If you’d get to more than quarter wavelength you would probably start getting issues as when a zero transition arrives you get counteracting induced currents. But this width is chose for how the wave resonates once coupled into the antenna. As it’s signifantly shorter than a quarter wavelen…

See wiedehopf’s comment re: radiation patterns and field strength. It may be relevant to what you were thinking.