Here's a use case for why filenames to titles are important.
It may also shed light on why Apple's current version did not implement it. For context, Photoshop released around 1990, iPhoto was available in 2002, USB 2.0 scanners in 2002-2004, the first digital SLR (under $1000) in 2003, Aperture in 2005, the first iPhone (including camera) in 2007. [I owned Macs from 1985 to 1993. PCs from 1993 to 2006. Macs from 2006 to present. When I moved back to Macs in 2006, the photos came over as files, mostly TIF.]
So therefore, the photos in my Photos library are of two main kinds: (1) scanned photos from prints or negatives in the era before digital photography. (2) Photos taken with digital cameras.
The scanned photos came from a flatbed digital scanner. They were scanned one by one. And the consumer level scanning software of the day did not allow entry of EXIF or IPTC data. The metadata was the file name and the file date. And the file date was fragile. File operation like copying or restoring from backup often changed it. So one carefully labeled the name of each file.
When I moved to the Mac, they were loaded into iPhoto and the file names showed up and they were useful because I had named each of the scanned photos carefully by hand. It’s this information that I’d like to automatically copy as the initial value of titles. These names are absolutely valuable. And being able to quickly copy them to titles would be wonderful. Applescript seems possible but quirky. I’m hoping Apple addresses this more directly
I agree with Apple that the file names associated with digital photography are much less useful. And also realize than many of their customers have few photos that came from scans. In fact all of this generation photos may be coming only for iPhones. But….....