With the addition an import feature from Kindle Highlights and other readers I do believe this would be a great feature.

These quotes could be submitted publicly for a book and merged with other users.

The quotes are to be upvoted and downvoted seperately.

I would love an export feature of my highlighted quotes as well.

One thing I like about Goodreads on desktop is their quotes feature. Pulling from a source like WikiQuote (https://en.wikiquote.org/wiki/Main_Page) might be a way to replicate such a feature for Hardcover