Are (computer science) workshops less prestigious than conferences in general?
Workshops are usually for new topics, and I do rank them lower than conferences. Moreover, workshops usually publish/accept papers rejected from their co-located main conference; often than not, they are used to prop up the number of registrations or to cover the cost of the main conference.  Also, because they are new, it is usually very easy to get a paper accepted as the standard is not there yet.  However, if the topics of interest grow and attract experienced researchers, then a workshop can be quite hard to get into, and hence, its prestige grows.