One of the issues that may have limited the adoption of Bitcoin is the fact that it takes 10 minutes to verify any transaction. This means that fraud would be a serious issue in any fast-food or retail establishment. Does this also apply to Zcash (obviously it's 2.5 minutes per block instead of 10 minutes, but that's not a significant difference)? Is there an intent by the Zcash team to address this now or later, or is it just not a priority?
If a merchant (or anyone) decides to accept payments without waiting for confirmation, they open themselves to the possibility of abuse.
Dash, for example, has addressed this issue with InstantX while the Lightning network attached to bitcoin is another solution for that problem.
How either of those examples apply to Zcash is up to the developers and users.