I think you are correct to change your stance Brad. Whilst it is true you can do harm if are not aware of the effect of what you are doing, that is the fault of the person involved, not the maintenance plans. The same sort of mistakes would be made (e.g. constant file shrinking) if the person wrote their own code to maintain the databases, they would just be putting more effort into making those mistakes.

Maintenance plans have their limitations but if they fit the bill for a database why not use them? For many databases out there nothing more than what they offer is required.

For me its all part of the KISS principle.