A waste to who? It's the editor of choice for a large number of people. It provides value to developers. In turn, the people who spend all day building it (I assume from a comment above) get paid to do so. Do you want to work for free?
I may be in the minority, but I don't think all code should be open. The people behind Sublime have made a great product and continue to improve it. Do you think they'd receive even half of their income if they made the code available?
Step 1. Remove nag message.
Step 2. Release to the world.
Day 3. Tonnes of people jump to non-nag version and never pay.
The plugin system and API is available for those that wish to complement or extend the editor. Making the code available directly harms their ability to make money and their ability to continue to invest time and money building the product.