I play for Fun... and it's fun to fly one place to another, make few fights - but repairs of ship costs, Nanobots and Shield Bateries - costs, mines & rokets - costs, Armod Upgrade - costs.
Nothing is for free - so actualy we need a money, it's part of roleplay, traders do trade - becouse of fun, and becouse it bring a money, miners mine for fun and becouse it bring a money.
so why Navy and Police cant? now the only way for them to earn some, is or not doing his job, and escort a traders, or make small misions for 20 - 100k, or create a sec.char who trade.
If i want to buy a gunboat or boomer to my RM i was forced to make a trader who earn a money for AU8, better guns, shields - so I fly my trader instead protect a home system.