I know I have posted this elsewhere but I simply don't get the worry about the money. By the time you are at the point that you can afford a carrier, you have surely reached the point that making even a 30m a week upkeep is easily possible in one play session. This isn't like that point in the game where you have just managed to make enough money to purchase the Krait but are considering holding out for the Python, that agonising decision that, in my case, took months to get to (I went with the Python).
I also don't understand the 'passive fees' objection. Again, for those that have been playing a while, making 100,000,000 is not a month long venture. I can do that easily, in fact, doing massacre missions for a week, I bet you earn that passively from all the extra you get from the bounties you cash in on top of the mission payments.
The one thing I sort of understand is the time constraints. You've been playing for years, accumulated a lot of money, you can afford a carrier but now you only get to play one or two hours a week, whilst the upkeep may not be a problem, certainly jumping the carrier and refilling its tanks with Trit is going eat up a lot of your playing time.
In conclusion, if you play a couple of hours a day and you have the money, get one. If you can only play a couple hours a week, I wouldn't bother.