From the article:

Google says it's removing XSLT to address security vulnerabilities. The underlying library that processes XSLT in Chrome (libxslt) is an aging C/C++ codebase with known memory safety issues. Chrome's team argues that because only about 0.02% of page loads use XSLT, it's not worth the maintenance burden.

It's debatable whether Google, with all its resources, really needs to do this, especially given that 0.02% of all page loads is still quite a lot. But there are certainly times when it's better to just delete seldom-used old code from your project to lower the maintenance burden and reduce the surface area for attacks.