Well said, as you pretty much narrowed it down to the target audience.
I have bought Wheels Mag in the past, but every issue was HSV vs FPV, even now when I go look at whats new on the magazine stand, it's always some HSV vs FPV top of the range and every so often they would make it a HSV vs FPV vs EVO X or 370Z or STi or an Exotic Euro.
As long as HSV and FPV are on the front cover, I guess their doing their job... Call me bias as I am Skyline enthusiast, still HPi has had GTR / Silvia Specials, segments on Supra, Soarer, Z, RX 7, EVO, STi, NSX, even a Ford Mustang was in HPi one time
IMO there is a bit more variety, mainly with the JDM cars.