Originally Posted by itimpi
If this updated the metadata AND cover, I do not see why it would encourage users to dig around inside the Calibre library? If anything I would think it would be the converse. I must admit I would welcome such a feature to avoid ever having to run epub->epub conversions to achieve this.
Since the metadata including cover is updated on any export from the library ("save to disk" and "send to device"), I stand by my reasoning: If you update the metadata from within Calibre, users might be tempted to just go into the library folder and pick the books out themselves for manual transfer. This can lead to Bad Things happening, as we've seen many times on this board. Kiwidude gave the only pro-updating argument I can see as being valid.