Every Product Manager and Product Owner must remind themselves that their product must meet customer needs or will become obsolete. It's not necessarily about more features. It's about if the customers can use them with ease.
This is fun and it could be super-useful. I'd love to do some analysis of this data set, correlating against Crunchbase data (sector, funding, etc) to see what could be learned and applied to future startups.
At-least a place for products that are no longer in use.
It would be great include a summary of why each gravestone is there. Afterall those who came after the mothballs will just find digital dust.