If you search both the Harley catalog and the aftermarket, you will find thousands of products that really aren't necessary or even beneficial to the motorcycling experience. As long as people will buy the stuff, other people will be more than happy to take their money.
I remember owning an excellent Honda product back in the early 80's that came standard with a digital gear indicator built into the gauge cluster. For the first week it was kind of a neat thing, especially back in those days when electronic gadgets were rare in vehicles. After becoming acclimated to the bike, however, I rarely looked at it. I expect this add-on device from Harley will be used even less, considering you have to take your eyes off the road and the gauges to read it. If they had really wanted to do it right, it would be mounted up by the gauges.
At least this is optional and you don't have to pay for it unless you want to. The stuff that fires me up is crap they put on the bike and charge you for whether you want it or not. So far my all time favorite in this category has to be the power lock feature on the CVO Ultra's. Not only is it superfluous on a motorcycle, it's money that could have been better spent fixing some of the many shortcomings of the basic functions of the motorcycle. How about spending a few bucks on the suspension for instance? The answer is that better suspensions don't have the same attraction for most buyers these days that electronic toys and doodads have.
Jerry