Its what the market will bear unfortunately.
In the very early days of GPS when I used to sell them as there was some profit in it in those days, the land units that were otherwise identical to the aviation ones were software limited to 100 knots max to prevent them being used in an aviation environment. Above 100 kts the display blanked out. This enabled a 200% price premium to be charged for the aviation version. It cause such a large number of complaints that Garmin removed the software limit.