I won't comment about what you said about the other things.. it's your opinion.
Anyway, about the Modern Carrier... if you say it's not needed, I guess you don't use Carriers much... I like wars in Civ (especially "modern" wars, when I have all tech - and without GDR, which is out of my games).
I play with "abundant" resources because I find it more fun this way. I use maps that have enough land but enough water too (like Continents, Small Continents, etc). I don't invade my "neighbours" all the time... sometimes I want to invade a civ that is on the other side of the map, on other continent. So, they have many ships, many airplanes (with abundant resources they can really have many) and a lot of ground troops. My tactic is to use a lot, and I mean A LOT of bombardment: from Jet Fighters, Bombers, Stealth Bombers, warships & artillery (when possible). My ground troops are not that many usually. I make more airplanes than ground troops...
So as an example, from a game: 30 Bombers and 9 Jet Fighters. I needed 13 Carriers for that ! With a Modern Carrier that will be able to transport 4 airplanes, I will only need 10. If it will be able to transport 5, then I will only need 8... that will decrease the maintenance, the building time, they will be easier to defend + the Modern Carrier should be faster too.
Also, new units are always good. Did we need WW1 units ? No... but having them, makes the game more fun and interesting. Now we have WW2 Carrier... I want a 21th century Carrier. At least for the look of it. Someone demanded a robot and they added it ! lol... and I want a carrier
I would also like to see a way to lvl up your Carrier. Like... it should be able to bombard, even if it's for really low dmg but at least it gets xp. Or maybe it can get xp when the airplanes on it get xp... I don't know...
PS: now I play on higher difficulties... probably I will need even more carriers