The most important factor tends to be the positive impact on society, as that's one of the price's core tenets.
One could also argue that in 1895, applied computer science and information theory would be considered physics.
Making it even more baffling that this won then
What about;
- Improved weather forecasts
- Protein folding
- Medical imaging and diagnostics
- Text-to-speech and voice recognition
- Language Translation
- Finance fraud detection
- Supply chain and logistics optimization
- Natural disaster prediction
Also, it's a price based on a will from over 100 years ago, managed by a private institution. The institution can be as arbitrary as it wants. They don't need to answer to anyone.