I'm pretty sure alien/human are interchangeable, please note if i'm wrong.

# Sharing off discourages players from building, because they know they will not have much revenues later in the game.
You either suck at building and like to suicide, or have never touched a conkit.
After not dying for 2 minutes, you get a 175 credit paycheck or an evolve. << Since you must now know about this... I refer back to my statement above.
Sharing off encourages feeding, because even a rifleman or a dretch will go out for kill, just to get revenues no matter the cost, therefore feeding the opponent team.
You learn to get that 2% dretch skill to 3%.
^
I'm sure you did read the benmach... oh wait, you didn't
taking a leading role in commanding a co-ordinated assault, is far less important to victory.
^
The "leader" is in front, he is "leading" the poor riflemen. He uses his "leading" skills to either take the blows, or dodge the alien. Typically, the poor riflemen gets some amount of credits even if s/he didn't kill the alien.
Sharing off weakens defences, because you have to go out killing just to get better weapons.
+ It creates an element of stratagy into this FPS game.
+ This is called Tremulous, not Campulous, you are trying to kill the other teams base, not to just camp and defend the whole game.
Sharing off makes you camp. Nobody with common sense will go out as a rifleman when tyrants are waiting in front of your base. So you are just there, waiting for a foe to near so that you can shoot him.
I will follow the leader out.
Sometimes, you are not lucky - you get killed three times in a row. Then, you are out of revenues. What do you to then? Right: You camp! Or you ask for revenues, get them, and go out again!
.. You tell them not to feed, but you ask them to feed.
If you die 3 times, odds are that the other player is better then you.. so it turn you are wasting team funds.
Sharing is good for teamwork for another reason: It does not condemn the unskilled player to eternal riflemanship or dretchendom - he can get revenues from other players and try out some things. I got a lot of my skills in that game because somebody once donated me something and said: Enjoy yourself, try out this or that. I did - without having to fear that I lose my hard earned revenues too easily and hardly ever get those again. My skills increased dramatically the time I avoided servers with share off.
2 minutes.. pow, a 175 credit paycheck and/or an evolve. OR, you follow the player who has the "leading role" and then you leech off his kills.
Sharing is also good for teamwork, because it enables players to remain what they are best in or - more important - they like most (games are mainly for fun, still, never forget that!), sharing makes it less important if you unluckily get killed too many times.
So you are asking players to only do things they are good at and not improve on their weaknesses. f33d me more!
Apropos luck: I cannot stress this too much: Even the best player can run out of revenues. With sharing turned off, he is f...ed. Sharing on makes skills more important than luck.
Obviously, if he is the best, he can get more money. He doesn't suddenly become worse because he is poor, he can still shoot and dodge, no?
# Sharing off makes you camp. When I have maximum revenues, why should I run into enemy fire/claws and lose it? I have nothing to gain, I can only lose something. But then, well, I can share away some revenues, and go out again.
Again, this is called Tremulous not Campulous.
+Yes. with 2k credits, you can go kill the alien base without worry because you have a something to get you back on your feet.
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I may have misread or misinterpreted something that you have said.
buuut
I know, I write too fast - slow readers cannot read it. But here's something for you: