Oracle's flagship database product is Exadata. It was initially a DW/BI offering, but has more recently become an OLTP consolidation box. The point is, the Exadata systems use RAC. That should suggest that RAC is suitable for DW environments.
The thing to remember is RAC used well is good. RAC used badly is bad. RAC used for the right type of requirement is good. RAC used for the wrong type of requirement is bad. I like RAC, but unlike everyone I don't think it is the perfect solution to every problem.