I have previously asked questions and read about the importance of always using a new address every-time you receive a transaction, even for change. Sometimes when I watch the block explorer I see transactions where the send address and change address are the same, like this one:
Tx: 7c99440257f45b2b87f655744a8ec4f87c73f54ca5a9873e083eae5214d51aa2
It is also my understanding that most wallet software automatically generates a new address for change. This leads me to believe that the transactions where the change address is the same might be people using more advanced wallet software that gives them more control over these features. Are there known reasons or types of users who intentionally choose not to follow the advice to use new change addresses?
1.
Poorly implemented wallet software. This also happens when you try to use Bitcoin as account based system even though each transaction with same change address used again will create a new UTXO to be spent later.2.
Freedom to create transactions in different ways as long as they follow consensus rules.3.
Speculation: Maybe the user doesn't care about trade-offs involved in using input as change and this setup works better for user. The tx shared in question has similar linked txs later, each using input as change and one output went to Coinbase exchange: i.imgur.com/g9wjpYm.png4.
Privacy: Things that a person doesn't want to share with everyone. Maybe this person is okay and aware of things involved. Sometimes using new change address also is easier to associate with same user.