This was true until Rosewill released their RG series. Prior to that, their reputation for PSU quality was pretty poor, although at least one unit from the RP series (Stallion iirc) passed Jonnyguru testing. Many of their units were overrated and prone to failure.
Beginning with the RG units, and continuing with the HIVE and CAPSTONE lines, they've cleaned up their act bigtime, consistently doing well in competent technical reviews.
Aqualipt's remark shows just how difficult it can be to repair a bad reputation, but Rosewill seems to be making a good effort of it.