TerraCoin doesn't really change anything in the bitcoin chain except for the block rate and diff retarget rate. I don't think it serves any useful purpose except as a pump n' dump scheme.
It doesn't matter if it gets 51%'d now or not, it'll be dead in a month due to merged mining anyway.
It's a pointless fork.
As far as I can see, all other coins excluding Bitcoin are flawed even more than Bitcoin itself. Unless something much better emerges,
having "backup" Bitcoin chain is good idea.
It's not a backup if it is subject to the same risks. That's why IMHO ppcoin is the only bitcoin alternative which adds value: It experiments with a different network security model.
All chains add value if the people who set them up educate themselves about crypto currency. Just because one set of people have already done it all and told everyone, doesn't mean there isn't educational value for others in redoing their work all over again. I'm a working fashion photographer- my whole incentive to be hanging out on the computer learning code is Cryptocurrency. Otherwise I would be out with the models. Trust me. It might seem like a horribel choice to everyone else, but I'm getting my kicks like this. So be it. That has value.
The only point I can agree upon is that you have more people developing and revising code. But there is no need to start a separate blockchain for that. IMHO the reason why people start a separate blockchain is because of the lack of funding. Pump'n'dump is currently the only feasible way to get a return on your coding (which is minimal if you just copy the chain). Right now I don't see it justified to buy into this blockchain. There is no proof of significant development other than keeping in sync with the bitcoin code.
Now it would be a different story if they had started development a while ago and would have augmented the code base significantly.
Maybe they are just tinkering around? They don't have to be doing it for outright profit no? And any of us can also go tinker with it as well. I think it hardly unlikely the bitcoin developers would pay someone like me much head, but with other codes and chains less experienced programers can feel free to experiment.
I think you could also agree though that it doesn't hurt anyone else- terracoin wasn't even announced here, we found it and hopped on. It's fair that they could be working on their own project, and we find out about it. It's not so fair if we see them building their own club house and we just go burn it down. :-(