Yeah - at the very least somebody will have to merge the duplicates by hand later.
It’s not too bad, although dates can be completely wrong sometimes. It’s also not ideal (and especially for classical music it looks nothing like the format we’d like to have).
That said, the main reasons are that a) it’s probably against the API’s TOS and b) it’s impossible for people to check the additions for errors if we add thousands per day. I definitely wouldn’t be against letting users import directly from the Spotify site with a button like with other importing userscripts though, so that the user is responsible for checking that the data is correct and not a duplicate