What makes the SPLC a "joke"? Actually the SPLC is well regarded.

Fr. Gruner's suspension is also described in a book, "The Smoke of Satan," by Michael W. Cuneo.

You wrote:

<<He had absolutely nothing to do with neo-nazis.>>

You know this how? As for your clumsy attempt to change the subject, Fr. Gruner is affiliated with hate groups because he affiliated with hate groups. To cite one example of Fr. Gruner's proclivities, The Fatima Center describes as "brilliant" the writings of antisemite Fr. Denis Fahey:

http://www.fatimacrusader.com/cr40/cr40pg10.asp

It has nothing to do with the Latin Mass.