The meaning of self-descriptive is serving to describe oneself : being or providing a description of oneself.

How is writing it in your twitter profile not "providing a description".

Also one glance at the actual data wouldve solved this missunderstanding. Pointing on others who made the same "mistake" is also a very weak excuse. You make a wrong claim on something that nobody asked for and now you want to push away responsiblity.

So id rephrase and say that you misslead yourself by assuming things before commenting while you had the possiblity to avoid this.