Please bear with me in asking this question.  My ignorance is getting the better of me and hope to present this well enough to convey the thought appropriately, and hope to get Christian Charitiable replies in return.
A family member of mine informed me of a 'school of thought' he has found worthy of following: Pope Benedict XV (15th) in the early 1900s promoted the thought that one must define themselves exclusively as Catholic. (To that point I would whole heartedly agree.) To define themselves as traditional vs liberal Catholic is wrong and is to be avoided at all cost.  At all cost being that to attend any traditional Catholic church (for example: locally my mother and I attend Mt. St. Michael's, known for its traditional Catholicism) is sinful and disobedient to Pope Benedict XV.  To attend the Modernist church of V-2 is also wrong, since they are the liberal side/watered down side of true Catholicism.  Without a doubt, they are to be avoided, as well...that, personally, that is not an option.  So the option for those following this theory is to not attend Mass or receive the sacraments, because, by definition most Catholic parishes define themselves as traditional or Catholic, in their opinion. To attend a SSPX or SSPV is also suspect as being wrong, because they are in line with a form of labeled traditionalism that is to be avoided.  
I want to understand this better, and feel I am missing something--can anyone (in Charity!) help me 'get this'?  To me this sounds  :shocked: like incorrect thinking, yet Iwant to be able to be more informed on it to understand it better!  Please help.