9 years overstay ?

they censored or banned the hell out of that site you mention ..

That possible 2 years in jail puts a chink in any financial advantages, unless you need free room and board.

It's easy to overstay as all the reporting to immigration relies upon voluntary compliance. The police don't check immigration documents, hotels look at a passport, but not visas. As long as you remain in the country you can probably get by.

Thailand has thousands of illegal immigrants from the bordering countries and Vietnam. They come to work at the higher wages here. (That's sure a sad statement.) I doubt that they are imprisoned for any length of time. It's cheaper to repatriate them or send them back to sea as a recent incident is being criticized.

It's easy to stay here if your meet the extension requirements. If not, you have to do visa runs or overstay and pay when you leave, risking imprisonment. I don't know of farangs being imprisoned for overstays, but that doesn't mean it hasn't happened.