There was a whole HN thread throwing up prior art about the linkification patent (and also on Reddit). Linkification was being done in the '80s, based on one of the programs that someone managed to scrounge up in the thread, and the '90s as well. No patents issued - people just did it.

The fact that these programs were written tells us that software writers innovate regardless of whether patents are issued for their work or not. That's the nature of software (and technology in general). The difference is, some software makers don't expect to protect their new features from competitors with patents. That's the crux of it, imo.