It is fine for people who are really keen to return to Thailand but too much for casual tourists.
On top of the requirements for getting CoE, people have to consider whether they will get stuck somewhere, end up in hospital for 2 weeks of their holiday (if they test positive), will have to unexpectedly quarantine on their return etc.
They will be wondering if anything will be open when they get there or whether things will shut down after they arrive.
The situation is too uncertain.
If you look at the way that conditions for lock downs are set up, world wide, on the basis of the dodgy PCR TEST, international travel isn't going to work. I expect a lot of our countries are going to collapse.