Well, that’s the entire point of accessibility. There’s a lot that “and” can expand into.
Sure, but then we’ve branched away from the topic. As no technology can include everyone I fail to see how excluding as small of a percentage of people as is feasible makes this bad without devolving into all technology is bad because it isn’t inclusive of everyone.
The badness of a technology would depend on how many people are affected and how badly (excluding some people always or excluding a lot of people randomly?), so I think we’re still on topic.
We’re just exploring all the ways that QR codes are good and all the ways that QR codes are bad.
There is no judgement as to how a person might weight those considerations. As @dcz says, if you did come to weight those considerations, while avoiding considering self-interest only, then you would want to understand the percentages who would be excluded - and before you could even do that you would have had to explore what percentages you are going to have to measure.
One consideration could be that there is a legislated right, or a right derived via some other means, such that excluding anyone is a legal problem. In other words, there would be a legal obligation to provide an alternative mechanism.
Example: Imagine a medium term future where all voting is done electronically using an app that is only available for iOS and Android (and let’s say, for relevance to the topic, scanning a QR code is part of the process). Would that be legally acceptable? Depends on the country of course but in most if not all democracies, probably not.
Definitely digressing now but there are some barcodes where the human-readable version is a representation that is only an approximation, and hence it is not possible to enter the human-readable version and get the same behaviour as scanning the barcode.