It's easy to think that Clark should have told Lois his secret in TOGOM, but that's because we already know how Lois felt about him. He didn't, and he certainly had no idea that it would be possible for Clark to come back from the dead. It would have meant his going to Lois as Superman and saying, "Hey, good news. Clark didn't die because I'm Clark. I hope that makes up for the fact that you won't ever see me again because I have to move away from everyone who knows me by sight and start a new life under a new name. I can still pop in and see you occasionally as Superman, but not very often since I won't be living in Metropolis. Alternately, I suppose I could just become Superman 24-7 and spend my time hanging around Metropolis in the blue suit and cape, but I don't want to put you in danger by linking you even more with Superman, so I won't be able to visit as Superman any more than I do now. Oh, and remember, you can't breathe a word of this to anyone and you still have to grieve for Clark publicly because my parents may be in danger if my secret gets out."
Yeah, I can really see Clark making that choice.
