oxymoron means two words that have opposite meanings used in conjunction. bitter sweet, loving hate, dark light.
subjective means that you are involved rather then distanced, objective and disinterested. From that basis yes you can have a stupid opinion or, if you prefer a less perjorative term, an unenlightened or ill considered one, like making a comment that someone is one of the worst players in the last 10 years at the start of their career rather than the end in particular a twenty year old KP. Even Isaac Weetra deserves that respect.
therefore my comment is not oxymoronic.
attack me for my comments worth by all means go ahead, but if you want to attack my language and call me a moron on the basis of that then i think it is you who is the moron.