While I don't use the name, I do consider it legitimate satire for the following reasons.
1. It sounds "Unamerican" and ties him to his immigrant roots, which I find legitimate grounds for satire given his statements and positions about immigrants.
2. He seems to set a very high store on the value of the name "Trump" valuing, iirc, in the billions. (I may be wrong on the number, am willing to be corrected.) I consider this sort of self-obsession mockable.
3. He once made fun of Jon Stewart for changing his name.
I think there is great value in the use of satire and other forms of mockery to expose the foibles of the powerful (yes, even the ones I actually like.) I, personally, consider this particular one to be rather weak and ineffective, but there is at least a small reason for it.
Opinions, of course, will vary.