Programatic thread bumping is inevitable, it can't be legislated without extreme measures like having gold sellers select a time-zone, restricting total posts on market, etc.
Very short sighted to think people will ever go back to manually bumping. Regressive design is very rarely effective and if you think there exists a problem in the market you should look at how you can make the market more effective to the community. The SEO argument is bs and I imagine you know...