What are the disadvantages of using likert scale?

The disadvantage of using this type of scale is that you can not make statements about some percentage of the population "agreeing" or "disagreeing" with something. The population is not being described in an absolute sense. You can only compare answers across groups or across similar samples over time. Additionally the rankings are dependent on the particular list given. For example, you might say that ice cream is good on a three point scale but very good on a 5 point scale.