The advantages of these tools are primarily seen from the point of view of those controlling the test execution, especially if these are domain experts rather than test analysts.
For test executioners it is easier to use keyword-driven testing rather than test script directly, because of the following reasons:
1) Keywords that reflect the business can be chosen
2) Test execution can be done automatically by non-technical people based on the keyword lists
3) The keyword list is robust to minor changes in the software
4) The implementation of the keywords is independent of the implementation of the underlying scripts, so that the same keyword lists may be used with scripts in a number of different scripting languages being executed in different execution tools