I don’t at all disagree w/ you at all, although I can’t begin to comment on Google’s implementation.
I CAN say from personal experience that for CVS, installation of their iOS app is a required precursor to installing their loyalty card into Apple’s iOS wallet.
I also see nothing in Apple’s documentation specifically about “loyalty cards.”
A “pass” is not considered the same as a loyalty card. (I’m not trying to play semantics)
I’ll use United Airlines (UAL) ONLY as an illustrative example.
Anyone can purchase a UAL ticket, via any means and when checking-in online for their flight can add a Boarding Pass to their mobile wallet via the web interface and go flying.
However, in order to install a UAL “MilesPlus” loyalty card (UAL’s frequent flyer program) a MilesPlus member must first install UAL’s iOS app.
After all, it’s UAL’s Loyalty program; so the implementation mechanics are entirely their decision.
Similarly, transit cards and sports tickets are not treated as “Loyalty Cards” but are more akin to pre-paid “Boarding Passes.”
I’m the first to admit that the differentiation can be subtle.