By your interpretation, using the word "selfish" will never add any extra information and "selfish utility maximizer" is a tautology.

Yes, you are correct. I'm sorry that I used the word selfish. If you had read my post before replying, you would have seen this sentence:

You may argue that pragmatics argue against this use of the word "selfish" because it thus adds no meaning. Fine. I have removed the word "selfish".

But, jeez, folks - can't any of you get past the use of the word 'selfish' and read the post? You are all off chasing red herrings. This is not an argument about whether rational agents are selfish or not. It does not make a difference to the argument I am presenting whether you believe rational agents are selfish or cooperative.