honda know their demographic, they know their customers dont give a damn about engine temperature, all they care is
1 - what is the speed (police)
2 - what is their fuel level (running out of it)
And their most beloved - does it play music? - Yes
deal done - customer buys it.
If you are looking for installing a gauge, its very easy to do but it will be aftermarket like a pod or a digital readout.