BE400 Captain questions the practice of using COM2 as the primary communication radio due to it's antenna location and frequent poor recption.

Narrative

This report is concerning the use of COM 1 on this aircraft; the 400XP. During this trip we had 2 instances in which we had issues during the taxi or on the ramp; and one while being cleared into position. That is 3 issues with ATC communications in the course of 1-2 days of flying. In every case switching to COM 1 was the solution to the issue. The common link was that all of these issues occurred at large; busy airports in areas of the airports where the lower antenna was not sufficient considering the obstructions conflicting with line-of-sight to the airport's antenna(s). This makes this issue even more critical. As mentioned; one instance was during the line-up. One instance was during taxi; with the Controller issuing new instructions; and as I recall one was on the ramp where it was not quite as critical. Each issue was at a different airport. On the 400XP; should a dual generator failure occur you will lose COM2 along with many other key items. We have; at best; 30 minutes of electrical power available in this state. I have argued; along with other Captains that share this same concern; that we should be operating on COM1. It would solve the taxi issue. It would solve the emergency dual generator failure issue. We have been told that it will remain as COM2 because of fleetwide standardization. That is a terribly weak argument. The standard should be that there is 'a primary radio per fleet.' We have been told that you can use the 1/2 switch on the RTU to look up the last frequency in the event of a dual generator failure. You can; but we don't train that and it isn't in the checklist. And; why would I want to be dealing with that when; assuming Murphy's law at its best; I'm flying at night in IMC on the peanut gyros with the First Officer reading the checklist with a flashlight. The last thing I will want to do is push the 1/2 button; remember the frequency; and tune the frequency on COM1. This is ridiculous when you consider had I been operating on COM1 I could have almost instantly declared an emergency with the proper controller. Remember; at best I have 30 minutes of electrical power. Over the past several years I have yet to hear a good argument for using COM2 as the primary. It appears it is the same logic as some other questionable practices; 'We have always done it that way'; or 'because I said so.' This needs to be addressed; and COM1 needs to be the primary. This trip alone using COM2 on the ground could have caused a clearance communication error; almost caused a taxiway/runway incursion; and nearly caused communications/clearance problems while sitting on the runway. Study real world operations with COM1 as the primary; verifying that there are no hidden issues. Study that data and make the change unless the data supports otherwise. Make policy based on actual data.