I've written before about how jobs are advertised and filled a little differently here as opposed to in the states. Its not uncommon to see a manager role advertised as looking for a male in his 30's or 40's, while an advertisement for an assistant role might specifically request female applicants in their 20's.
Selling lottery tickets is primarily the domain of individuals who are blind or in some way disabled. This is often done on the street or possibly from a small booth in a shopping area. Perhaps this is the country's way of trying to help those individuals who might have a very difficult time finding other work. There is no Thailand with Disabilities Act which requires employers to accommodate and individual's disability. If you can't physically do the job, you aren't going to get it.
Recently, the lottery ticket sellers gathered to protest wages or working conditions. The government invoked the still-in-effect emergency decree to force them to disband. Photos of blind and disabled people jumping into the canal to avoid being arrested by police was probably not the government's idea of good publicity.