I disliked Thailand for the same reasons. I only spent a couple of weeks there (part of a backpacking trip in SE Asia and Australia) but I noticed way too many scams and issues.
I backpacked in a bunch of countries all around the world and never had much problems. But I found Thai just blasé with tourism. I can’t blame them too much either, there are some seedy tourists…
My best memories were in Southern Thailand, by the border with Malaysia.