Even without grinding your own mirrors, a lot of thought can go into the sensor, telescope, tripod and tracker, filter selection, exposure times, etc. Some of that transfers, some doesn't. Not to mentions the hardships like lugging all your stuff to the nearest desert and staying up checking on your shots and swapping filters. Necessary? Maybe not. A point of potential pride? Maybe.

Also I do happen to know at least one guy who grinds his own stuff. Legend.