Is it empathy, or is it the realization that the decline could be worse if they develop a Nestle-style reputation and inspire boycotts or something? I won't rule out empathy, but it's not the first thing that jumps to mind for me.
Which therefore fits the term altruistic, whether they intended for this or not, as other businesses have not replicated what Starbucks is doing.
With all these possibilities, alongside a potentially contrived ideal of a founder to actually subsidize public bathrooms for all, doesn't that mean it is useless to debate and just accept the reality at face value of "they are providing a service and its nice"
An example for background (incomplete list of stuff they do): https://www.zmescience.com/science/nestle-company-pollution-...
I think the world would be a better place if we judged people based on action rather than intention. Intention is complex and hard to determine.