eao,
Don't be so quick to condemn your DBA.
How complicated is the database update? If it is a very simple update without a whole lot of data massaging taking place, then using only a Job may be appropriate. Using the principle of KISS, why involve both a DTS package and a scheduled job if you can accomplish the task by using only a Job?
On the other hand (and this is something I have not had personal experience with, so I am only speculating), I have seen that error messages from a SQL Agent Job (at least when running a DTS package) are not very helpful. In the ease of maintenance category, I would have to say DTS (at least in my experience) leave the SQL Agent Job in the dust.
And, maybe it's just that your DBA does not have experience with DTS and doesn't know its capabilities.
Is it really worth it to butt heads with your DBA? For now I would say that if you can do the update with only a SQL Agent Job, go with that. Later, if a problem arises which DTS could take care of, point this out (in a helpful, friendly way) to your DBA. Also, make a case for DTS vs. SQL Agent Job and present it to your DBA. Cooperation works a whole lot better than confrontation.