It's a heck of a lot earier and cleaner to install guard rails around the edge of a bridge to prevent people from leaping, than it is to install a net to catch people after they've already leapt off.
In additional to misguided developers, it's also possible for a miscoded application or ETL process to trash tables in the production environment, so it's better to just tighten down the database with constraints and least privillage accounts.
"Do not seek to follow in the footsteps of the wise. Instead, seek what they sought." - Matsuo Basho