There are programming limitations with higher numbers unless you are only fine with two or three decimal places.   Otherwise I actually agree with your points with the supply. 

 It could very well be the case that digital currencies could be a $Trillion(s) industry some day so naturally the front runner and runner up coins should have a supply which matches this scale.  If you are talking about a lot of coins with a capitalization between $20 billion to $500 billion then the best supply here is probably in the low trillions.






People want to psychologically think they are getting a good deal, like exchanging $1 for 10 of *insert coin*.  In the reverse case, we're seeing people whine because they don't even have the disposable income to afford a single BTC and that's discouraging user adoption.  There was a time last year that a single BTC went for the equivalent of an apartment's rent in a lot of countries and not everyone in this world is making enough money to spend $1000+ on a high risk "magic internet money" coin that could go down to $0.


As for people who want anonymity - I'm not sure if it's works as trust is built around having a public ledger so anybody in the public can do a public audit.  Granted this is an invasion of your privacy if people can link your wallet to say the Bunny Ranch but there are already proposed solutions like coin mixers and maybe in the future payment processors who'll keep your anonymity.