Marking the funds as unavailable would cause great issue for people using checks. For example, a rent check would only be good on six months?
Who would accept this? The law was initially written to protect consumers from having their money unavailable
- Pending
- Pending with funds available
- Cleared
A year later, the internet will have thousands of threads on various sites with people complaining that their (real, legitimate) paychecks still show the indication weeks after depositing.
People who are so wishful-thinking that they think someone is paying them a 10% commission to deposit a check will still be wishful-thinking, and will continue to accept statements like "this is normal, you'll see it all over the internet" at face value.
As I understand it, there is literally not a "transaction complete" message in the ACH protocol. After enough days without hearing an exception, you assume it went though.
U suspect this comes to the implementation model-- since it's so much based on batch files and potentially offline processing at the destination bank, they probably don't want the overhead of composing and returning a success response for the 95% of transactions that behave normally.