Clean oil is way better than dirty oil.
Synthetic is way better than conventional oil.
This issue, technically, should no longer be devisive. Those that disagree now with the use of synthetic oil are likely to have disagreed when it was first available, and are likely to disagree until they die.
But remember, that does not mean there is a logical, technically accurate debate. It simply means that there are some (smaller number each year as the knowledge sinks in) who disagree.