you don't understand at all. Those people weren't using "legal pathways". They were taking advantage of the country turning a blind eye to misuse of the exempt entry. These people wanted to live in Thailand but didn't want to apply for visas, and they are upset that what the exempt entry was always intended for, is being enforced.
tourist visa gives you 60 days in the country. Which you can extend by 30 days. The exempt entry with no visa also gives you 60 days which you can extend for extra 30 days at local immigration.
90 day visa is the validity period to use it to enter Thailand. Then once you land you will be given 60 days stay in the country. If you have a passport from one of the eligible countries you could enter exempt of a visa for 60 days.