I think that many times, as much as Paul may not have wanted it to be that way, his "pharisical" side came out.
Some of his views were quite "unchristian" at times, but one thing we need to remember is to NOT take the minority of what Paul worte over the MAJORITY of what he wrote, Paul's passages on love are still some of the most beautiful verse we can read today.
Fact is, while Paul mentioned "disassociating" from one Person, he mentioned far more times loving people and no where else in any of the Gospels or other letters do we see any recommendation for "disassociation".