Quote Originally Posted by Endemerrin View Post
The Allagan Empire reigned for about one thousand years. Xande was both the first emperor, and the last emperor after his resurrection. In 1.0, it was said that the Crystal Tower was built as his tomb, though they may have revised that and/or the NPC that said it could have been incorrect.

If that's the truth, however, that would explain the construction, given that the Allagan Empire likely wasn't building space ships until the end of their thousand year reign. When Xande originally ruled, the empire was probably at a technological level similar to our own, if not even further behind.
That doesn't mean it can't be retrofitted. Dalamud was built to complement ST.