You're totally wrong. The visa was designed to get people into the country spending money to give the economy a boost. A few deluded people think the 180 days ties in with the "tax residency" which it doesn't. Most people getting DTVs will be spending a lot more than 180 days in the country each year. I'm on non-O which is a one year stamp - you might as well say that has everything to do with tax! đ. I've been in Thailand for 23 years, and probably 16 of those as a "tax resident" but I don't pay a single baht in income tax because I'm a tax resident also of Australia, and Australia gets sole claim on my taxation. That hasn't changed, and won't change. Nothing to do with visas, everything to do with "assessable income"
Your question has no validity as there is ZERO connection between ANY visa and taxation. It's that simple. This group is about the DTV, not about taxation
It will be voted on in Parliament in January as the government is proposing to include the 300 baht tourist tax as part of the online ETA application process, so I wouldn't be expecting it to be introduced until February at the earliest