well maybe that one person needs a team, maybe some People from the community or he can just hire a team, and if he needs money to do so ill pitch in some money, maybe make a fund raiser.
Well okay, first all the members of that team need a thorough understanding of an outdated version of Torque, the new engine, and Blockland itself. Then you go through all the game's code and find ways to implement all of it into a new system of classes and procedures. Anything created for Blockland has to be recreated in the new engine, and modifications to torque for Blockland's sake have to be discarded while hammering the new engine into shape to support all the same features that the old one did. Next, the script files. All of them have to be rewritten completely in a new scripting language. Probably have to re-export all the models to a new format, too. Oh, and maybe triple the time it takes to do that because contrary to popular belief of people who don't know anything, working as a team on projects doesn't always make things go faster and can often make things go slower. Finally, there's the mountain of add-ons the community has created. All of them have to be ported.
What would be the payoff of all this? Well first of all the community would be torn in half when the new version still needs months of bug fixes to work as well, the newer engine would probably require better specifications rendering many people unable to play the newer one. The old one would draw a large percentage of the playerbase with tons of add-ons while simultaneously decaying due to lack of support and no promise of future content, driving many people away from the game entirely. The remains of the modding community would be further reduced by the need to learn a new scripting language. The new engine would also probably have its share of limitations, too, so I doubt even the decline in people whining about the engine would last long. Of course, the community could be rebuilt over time. Thus, as far as I can speculate, the costs and effects of porting Blockland to a new engine are roughly equivalent to if not worse than just making a completely separate game.
tl;dr: If you don't like the engine, go make your own game.