Maybe this is the case. However, from the outset this software seems highly dependent on iCloud for full functionality.
The basic truth is that I do not trust iCloud with my photos. Music? Sure. Phone contacts, syncing app preferences? Why not. But my photos?
This is the most precious data I have. Nothing else even comes close. My music collection is replaceable. Photos are not.
Without this trust, this software becomes nearly useless. I can use it for "messing around" but not to seriously store my photos. The approach seems to be putting the "master copy" on iCloud. NO WAY! The master copy needs to be on the computer. Every other copy should be a backup of it.
That's the fundamental problem for me, and I'm sure many others. We're not willing to risk our photos; they are too precious. If I had to lose ALL my personal data except ONE kind, I'd pick photos to be that exception.
You're much more likely to lose your photos kept on your own computer at home than to lose them on iCloud because you likely don't have the capabilities for redundant backups and protection from fire, flood, theft, drive failure, and other circumstances. In any case, the new Photos app for Mac stores all of your photos on your Mac as well so if you have Time Machine turned on, you get local backups in addition to iCloud. Pretty much a perfect scenario.