Thee criteria classes both provide ability to filter by resource type name. They need to complement that with the ability to filter by plugin name, otherwise it will not be possible to lookup a resource type that is defined in other plugins with the same name (e.g. the "JBossAS Server" restype from the JBossAS plugin).
Note, the workaround is to first lookup the desired resource type using ResourceTypeManager.getResourceTypeByNameAndPlugin() and then filter by that resource type's id (rather than name) in the AlertCriteria or MeasurementDefinitionCriteria.
Still totally true, Adding this for the next release (4.12).