There are many reasons why this is attractive both to the developer and to companies in general. Scala is a concise and highly productive programming language. By using Scala on .Net, developers can produce applications more quickly and have the possibility of deploying them across the two major industry platforms, JVM and .Net.
For the programmer it makes a great deal more sense too, learning one language to build applications for both environments. From a company point of view scarce resources, good developers, can be moved easily between platforms reducing training costs, increasing flexibility and reducing risks. .Net provides an integration platform for several languages and this implementation of Scala inter-operates nicely. You can use existing .Net libraries or applications without re-writing everything in Scala. A low risk way to explore the potential of Scala. Ultimately it means that many tools and applications created for the .Net and JVM environments can be ported from one to the other. A win-win situation for everyone.