So long as the town is properly protected so that only happy or ugly can destroy those diamond, iron and gold blocks then it is fine. They have donated for creative, I don't want to have to get really restrictive on this kind of stuff but if it becomes a problem, it will leave me with no choice ... the other thing is a looks really tacky, but we can't all be great builders, at least show bad builders better buildings so they can get some inspiration.
If you want to help then certainly check a towns permission ie /town <town name> and make sure residents/outsider etc have destroy turned off. Or make sure there is sponges protecting it.