I don't know that much about Thaksin as his time in office was maybe about a year from ending when I first came to stay here in Thailand, but when you compare it with now especially with no enforcement of this 90 day reporting treating expats like criminals on parole, among other things, to today, the immigration issues are far much worse now than they were then, especially since 2014.
The ex unelected PM's term of office should surely be looked at as it would seem the country became much worse between 2014 and now. He should be jailed for leading an illegal coup just on it's own, never mind all that wealth he accummilated.
Spidermike007 nailed it right on with his excellent post a few post's back.