Never knew Improv existed. There are tools that are similar to the vision of Improv. I use Anaplan at work everyday and it is exactly what a modern cloud based SaaS version of Improv would feel like. It is a multi billion dollar company and it worked because it did not go after the spreadsheet space but played along nicely with it.

The Improv article concludes "the key strategy mistake was to try to market Improv to the existing spreadsheet market. Instead, if the product were marketed to a segment where the more structured model was a ‘feature’ not a ‘bug’ would have given Lotus the time to learn and improve and refine the model to a point where it would have satisfied the larger market as well." and Anaplan seems to not have made this mistake. They have carved out a niche in the EPM (Enterprise Performance Management) market.