That's a fake IDP, that's why it isn't valid. You probably got scammed by one of the many online websites offering IDPs. IDPs are only authorised to be issued by specific agencies for each country's license holders. For the USA, it's AAA, for the UK, it is the Post Office, etc.
what other countries do has nothing to do with Thailand's procedures. Thailand has not stopped issuing exit stamps unless someone used the automated channel. Imagine trying to argue with Thai immigration that there is no requirement to have an exit stamp from Thailand just because Australia doesn't do so.
that's strange to hear. My personal experience and that of every other post I've seen from pet owners is how professional and easy it is. Did you follow all the regulations and requirements before coming? Otherwise, you can't blame officers for imposing fines or following the rules for animal importation.