[spoiler] um...Could we not just have come back for him?

[WALP]

Initially the scene where you must choose whether or not to kill Simon-2 made sense. You had a clear dilemma:
1. Let him wake up lonely, and left behind by you and Cath who have gone to phi.
2. Kill him

Both of which are not exactly pleasant options. With this mindset I chose to drain the battery of Simon-2, but in retrospect I think I may have misunderstood option number 1.

Let's say we let him live, and then skip forward to after the ark was launched into space. Could we not just take the elevator back up to him, making him not lonely? in fact we could be back before he even woke up, since Catherine put him to sleep for a few days. So now it's:

1. Let him wait for you to come back. Then you can figure out what to do from there, or just have a collective suicide or something.
2. kill him.

Even if it end's up with him having to die as well in option number 1. at least then he wont have to die lonely, or being deceived.

I can understand based on his reaction to the ending, that Simon could easily have misunderstood option 1, but Catherine clearly knew she would still be here after launching, so why was she so panicked about it? is this a plot hole? or is there some unknown bad aspect of this option that I am missing?