At first, there is some misunderstanding of Standard and Indirect.
Direct and indirect encoding are the same things from standard's point of view because there is standards on how to create and how to decode 2D matrix but not on what must be inside. Yes, DoCoMo stepped further and created standard on what must be inside. The differences exists in proprietary encodings like ShotCode because they designed to carry ID only and cannot keep general URLs.
As I wrote before, direct encoding can work the same way as indirect if you point it to your proprietaty service. But then, why do we need complex data inside then just ID is enough? ID based is better as you said - no needs for macro lens and focus, at least. then more resistant to partial damages.
Everybody understands that: less data inside means less complex code and more readable it is; and, end user is NOT INTERESTED in technological background at all.
It means that this discussions are for professionals and more related to business protection that real technological benefits of one thing over another.
AT&T, O2, Orange and so on are interested in simple yet effective service and they will force companies like mine or NEOM use universal readers. You are right - 5 different readers is a direct way to either mental house or no user's activity at all. User do not know what reader to use and when.
That is why, for instance, I am getting about two requirest on implementing proprietary resolution services into iMatrix! Companies understand this from the beginning.
But because this market is wild at the moment a lot of companies try to push thier reader to exclusive position:))
In a some time we will have the only readers for particular platforms.
Hence my answer is - all these 2D codes cam and must co-exists:)
ID based thing is more secure and more advanced. Simple comparison is: cash or credit card. Cash is URL based encoding, Credit Card is just at ID.
I think I found good example.
At again, as market is huge, a lot of code standards will co-exists, may be even forever.
