Its more the first point than any others.
Having multiple freqs for all controlled aerodromes would make it necessary for you to access and understand charts and enroute supplements, designated airpsace handbooks etc.
VHFs range is actually pretty decent when your talking aircraft. On the ground its about 5km-10km sort of stuff but u get 1000ft in the air and a recvr will pick up your xmit for 50nm no worries. At high level, vhf range is out to about 220nm or 250-270nm over water.
Having all controlled aerodromes on the same freq in RL situation would be a recipe for disaster and im pretty certain (and speaking from experience) that any controlled aerodrome will have its own discrete frequency to use that requires a pilot to contact for clearance to enter their controlled tower steps. Any replication of frequencies (both enroute and tower) is done such that theyre at least 300nm apart. An example of what would happen with 1 freq would be melbourne and essendon airports. They are about 3-5nm apart. Aircraft on approach using the same frequency to these 2 airports would end up breaking speration constantly if they were trying to clear landings and departures on it. Pilots would hear multiple ATCs issuing instructions and when i pilot called 'tower' he'd likely get 2 responses.
Pilots both military and civvy (and the military have to operate in the civvy system 95% of the time) will usually have the charts available to look up if they need if theyre too lazy to actually do a full briefing that would involve noting down the freqs required either on a kneepad or on a briefing template notepad.
In civvy air control there is a 'common' frequency for uncontrolled aerodromes, usually known as a 'CTAF' which all VFR traffic needs to monitor and broadcast when in vicinity of uncontrolled aerodromes whether overflying in G airpsace or landing/departing.
So in a way the 127.5 freq can be thought of like this if you want to try and inject some realism into it.
but i wouldnt worry about it, its been done for simulation simplicity sake and thats about it.
having said that, theyve gone to the effort of putting NDBs (inner and outer, which i can only assume is reference to a localizer rather than a straight up single NDB) in with specific freqs at each aerodrome.