I get the sarcasm, and yeah it's like that in the "real world". But it creates a situation that is impossible to get out of in the game. Take for example, Liaedin system. It is an Empire system deep in Federation space. The major faction is Patron's Principles and there are 3 or more other factions. I know there are 2 empire sub-factions (Patron's Principles & something Electronics) and at least 1 federation sub faction (Crimson Fortune Company). There are three stations in the system. Patron's Principles owns all 3 since I poked my nose in the system. Back then, Patron's Principle had 80ish influence, Crimson had 12ish and the rest were insignificant. I did all I could to prop up Crimson, but there were almost no missions for them to complete. With a full bulletin board, 8 out of 10 were Patron's missions. To top it off, being the only Empire system deep in Federation space, it is a hotspot for CMDR's that want to cash in Bounties accumulated with KWS's. Each time they do that, it bumps up Patron's influence because they own the stations. Traders that run the system, bump up Patrons because they own the stations. Explorers that sell at any of the station, bumps up Patrons because they own the stations.
I have seen Patron's Principles go as high as 96%, with all the others at 1% or less. The last time I checked (which I don't do often any more since there is no mechanic for me to support Crimson) Patron's was at 85% and the other Empire faction was at 10%. All others were at zero.
All I do now, is if I see a Patron or Electronics mission, I take it and use the alternate mission objective to damage their influence. To no avail, it is few and far between when either will give me a mission, since I am "hostile" to those two sub factions.
So, in reply to your quote: Is it realistic? Yes. Is it a good game mechanic? No.
My suggestions is to allow me to sell my commodities or exploration data to any sub faction, even if it means a reduction in profit. Always have a full list of missions for all sub factions, their worth scaling with their influence.
Otherwise the rich get richer, and there'll be nothing to do in the game but make Credits.