These dilapidated houses are on Xemxija Hill, the main thoroughfare between Valletta and Gozo.
If the government had a real interest in embellishing the island, providing housing for the young and earning some much needed income, it would impose a tax on empty buildings and buildings that are not completed within three years of the granting of planning permission.
However, as Maltese governments tend to be clientelistic in nature, I very much doubt that any such thing will happen.