It's not a rule but a policy. Same with the extension of stay for tourist visa. The policy to extension a tourist visa is supposed to be in case of an emergency not as a norm for longer stays. So if the immigration officer feels you're abusing your privileges, the policy (not a rule) is to refuse you the extension.
It clearly says you need a visa fit for the purpose of stay and if you're on many single entry tourist visa (or visa exempt) back to back, then you obviously have the wrong visa and you should have gotten a multiple entry tourist visa which would be fit to stay as a tourist for a substantial time.
Show me just one single incident of a foreigner being in IDC because he didn't pay a bribe. How would they even know who complained about them from thousands of complaints they receive? Please enlighten me.
Although there are plenty of people serving jail term for bribing am official and I know several officials who have been fined, demoted or reposted to some tiny village in Nakorn Sri Nowhere.
The Thai Criminal Code criminalizes both active and passive bribery. According to Section 144, the punishment that may be imposed for the bribing an official is imprisonment up to 5 years or a fine of 10,000 THB, or both. This includes even the offering of a bribe to a policeman or other official and can result in jail time.
If you're cowardly enough not to stand up for what's right or wrong, that's entirely your choice. You might reflect about it once YOU sit in detention š
As for being the right or wrong place for me? Well I've been pretty fine for the last 40 years here inThailand, without paying bribes.