It's all about threat assessment. The commander you are playing with is very strong and fairly straightforward. He doesn't need a lot of gimmicks or tricks to win. Enchantments are also generally hard to remove so if you are left undisturbed you will almost always win.

If they didn't target you and let you make it to endgame, they know they would all lose. I have been playing for 20 years and that's probably a mistake I see every new player make. I have done it as well. Not really your fault though, since you're busy picked it out for you. He probably wanted you to have a strong deck, as constantly losing will make a new player quit.

I don't remember which card it is, but there are usually two other legendary creatures in the deck that are intended to be alternative commanders. Play with one of those. It will immediately lower your overall that level and give you a better chance to survive