The quality of the encryption is debattable, but you're right about the online mode only. This was clearly the best protection possible when it's been decided (early 2011). Surely, some clever guys could crack it, like any other title, but it seems that R3E doesn't deserve this honor, which is easy to understand considering that it was less popular than most of the others racing games until the end of last year .
A lot of people got used to online games along the years, and I don't think they'll all dislike it suddenly.
FS 2020 will probably become one of the most popular game/simulator for the next 5 years at least, and it's pretty much playable online only.
R3E's editor (Raceroom) choice to make this game exclusively online is not necessarly what Sector3 Studios would have opted for, but I must reckon
it protected us from bankrupcy or worse for quite a long time already.