Why don't they.....?

[lilabner]

Make a rangefinder that will show the effective range of targets that are significantly higher or lower than the shooter. You have to hold low on such shots, but you must guess how low.  It should not be difficult to build one that measures the tilt angle, calculates the length of the other sides of the right triangle and gives you the range figure to use for actual bullet drop. Should be great for mountain hunting.

[TheOpticZone]

Sounds like you are talking about the Bushnell Pinseeker 1500 Rangefinder with Slope.

[lilabner]

Thanks, Jon
I'll check it out. For hunting, I don't see a great need for the feature except for sheep and goat hunting but it would sure be helpful for them.