It wasn't terribly fun for me either but it sure beats the hell out of tapping a respawning node or repeatedly grinding missions. What it needs is difficulty scaling player, activated or region based, to provide a 'challenge slider'. Something that Thumpers lost too easily was challenge because gear out scaled the encounter and it was predictable and almost static or too methodical. Movement and JJ really killed a lot of the AI's ability to function too.
That might be more why it wasn't your thing?; thats what killed it for me at least.
Do not forget that Thumpers got a "exclusion" zone which prevented other thumpers from being put down near them, thumpers were required to be put down on resources, and that melding thumping was removed.
Back in early CBT melding thumping was one of the big group activities. Drop 2-4 of the massive thumpers by the melding wall and brace for combat, a lot of shit was coming your way and it was going to be a war. That was also one of the ways to consistently get chosen to spawn when you wanted them to. They would come marching from the wall with a vanguard of melded creatures.
Sure, when the thumpers were done most of what you got was dirt that you would have to chuck into the printer for sifting, but the ability to create a massive battle appropriate for a big group was fun in and of itself.
Course that thumping was done long before the game was made so vertical...