Come on, we are all developers here I want to think If I see a feature is just for aesthetic reasons with little purpose, then I could be considered as code sanitization, nobody really needs a transparent terminal, in the contrary, it may be contra productive.

I don't agree that aesthetic features have little purpose in a desktop application - they are a major part of the user experience. In this case the transparency feature is clearly something that a lot of people consider worth having.

Except they don't give a valid explanation for it.

Yes, they do - there are lots of them in this thread. Either you are not paying attention, or you are making assumptions of the validity of other peoples experience that you have no basis for.

Everything in life is not about productivity. But even if it was, the aesthetics of your environment does impact productivity. Personally I do continuously tweak the appearance of my environment because being relaxed and at ease makes a big difference to my concentration, which makes a big difference for how easily I get in the zone and is productive.

To presume that a feature that is "just for aesthetic reasons" has little purpose is arrogant and/or implies a lacking understanding of other developers.