It definitely wasn't to prevent mods if mod tools have been planned to be released ever since the online only was announced. Use some common sense.
lol. You've never modded obviously. One of the things we did in the modding community was to build mod tools.
Eventually SOME developers included them. But mostly we built our own tools or found other ways. Heck, I remember when we used to ASCII text-editors to mod games... Of course, that was in the DOS 3.1 days...
Hackers open up offline play, modding tools for SimCity
EA and Maxis' claim that it would take "significant engineering work" to make a workable offline version of SimCity took another hit today. Hackers have released modding tools that disable the game's periodic server checks without breaking the simulation. The tools also unlock other features not in the final game.
And, of course, it was pretty easy because the game was promised to be moddable on release:
Last year, SimCity Creative and Art Director Ocean Quigley said the game was being "built to be moddable" at a GDC panel. He reaffirmed that stance in a tweet just last month, indicating modded package files would be allowed (but maybe not directly supported) once the game was released. Given the potential for menace on public servers being quickly unlocked by players, however, this stance may not last.