I'm not sure that I can answer effectively without stating how altruistic I consider myself to be. I feel that I am a semi-altruist -- I assign higher utility to the welfare and happiness people I am personally attached to and myself, but, by default, I assign positive utility to the welfare and happiness of any sentient being.

I found your post offputting because it looked like a covert argument for altruism of the following form:

1. Eliezer and co. are altruists
2. Eliezer and co have written material (especially) to help altruists, and you have benefited.
3. Thus, you should be an altruist.

To me, this resembles an argument from authority and possibly an attempt at trying to make people feel that they should pay for goods already received.

This, this, and this are appealing to me as emotional arguments for altruism, just in case this helps you get a better idea of where I am coming from.

Edit: Click on the "Help" tag on the bottom left of the comments box to see how to italicize words in comments.