Several reasons: 1. Martin Grigorov (Wicket committer) and Michael Haitz (similar Wicket expert) are working on ISIS-537 [1] to restyle Wicket using Bootstrap3. One of their key dependencies is currently only available under JDK 1.7.
2. Wicket 7.0 will mandate JDK 1.7, and, obviously Isis' Wicket viewer should keep up with the latest version of Wicket. 3. its 2013 already. Any votes +1 or -1? Thx Dan [1] https://github.com/l0rdn1kk0n/isis/commits/ISIS-537
