I agree, however, for those not using DBRE, creating and dropping tables for unit tests which Roo users have been used to may cause issues for them if the behaviour is changed. I view the DBRE tool primarily as a means for prototyping from a schema which is typically controlled by a data modeller and/or a DBA during the design phase where data is not that important.
In previous companies I've always had a separate test configuration in the src/test/resources tree which is used for unit tests and usually points to a different database whereas the production/UAT schemas are accessed using the src/main/resources tree. I will look into this again, as I know version 2.8 of the maven-eclipse-plugin facilitated this for running unit tests in Eclipse as the src/test tree appeared first in the classpath order, but we are using 2.7 due to an AspectJ issue.
At worst, I will change the default configuration to use "validate" and document this for users.