Cramming might actually be the most time-effective strategy for a short recall period (one off exam). But naturally not if the aim is long term recall.
It is. We were specifically dealing with ESL/second-language learning though. Long term retention is necessary for fluency. If you want to pass a driver's exam or material you don't really care about beyond passing a test, then cram. Although in most classes, you will probably want to retain knowledge beyond a month in order to do well on a final.