Your model of "selling out" is wrong. He did change his values for a holidays or a Winnebago. He has been aligned with a certain set of values for a long time, and has not really changed. He got the position he is in because of those values and other attributes. People give him gifts, do favors, etc not to curry favor with him or attempt to change his rulings. They are saying "thank you for upholding our values in the Supreme Court".

Also, you should be careful of the sources you get info about Justice Thomas, as you are propagating racist coded tropes.