Though I had given my concluding remark, but your reply prompts me to put this final post on the subject. After having a look at your profile, I can understand your insistence on sticking to the academic definitions of things. I am a corporate decision maker and have of course studied business as well. My comments or opinion are a blend of my experience and academic qualification.
Academic definitions do provide you the starting end. By my dear friend, when you are in real life and in real business environment things are not as simple. Business decisions are not based on academic models. Academic models helps in developing the embryo level of concept. As business feasibility is further developed practicality demands decisions, modeling and investments; which are not supported by academic modeling. If you look at business history you will find great stories are result of unconventional decisions. In today's business world whoever has tried to implement the true academic definition into practicality, they have ultimately suffered more then gained.
Tax collection is a business, with prevailing problems in our tax system, injustices in tax imposition, practices of tax evasion and a large amount of economy being operated underground are the reason, we should look for a more out of the box tax system. E.g. an unbranded burger shop does not pay any tax. Despite the fact that they earn more than you and me. How to bring them in tax net; very few want to surrender to tax authorities voluntarily. Deduction of income tax on bank transaction is not an indirect tax. It will be a direct tax on individual who is paying it. It will be final tax regime, so no one has to file any return. Lets have an example. A person having yearly income of 750.000 is now taxed around 35000 ( not the exact tax amount but around it). As per my recommendation his tax amount through bank transactions would be maximum 30,000. In most of the cases it will be between 20-25000. Now tell me which system is better present or a 2% transaction system, especially when 16-19% GST is not there?