The key point is that "first to file" doesn't actually honor the idea of invention. It honors the idea of filing the patent first. So, now it's a race to file instead of invent. Perhaps the patent system has behaved this way for some time, but it's codified now.

From wikipedia: "In a first-to-file system, also called "first inventor to file" system, the right to the grant of a patent for a given invention lies with the first person (the first inventor(s)) to file a patent application for protection of that invention, regardless of the date of actual invention."