To be honest, I don't find those reasons valid.
If you sign up for a correspondence game, please sign up for time parameters that you can meet based on your circumstances.
Then meet them.
It's really as simple as that.
"Oh, I'm losing, and now it's too much of a hassle to go to an internet cafe, so I'll just time out and it won't affect my rank" does not cut it at all.
I think that a rank penalty for timing out is entirely appropriate. I think the "T" for timing out should last much longer - maybe a minimum of 6 months lets say - to warn people that you are a timer-outer, so they can chose not to play with you.
Like BHyden said, if OGS became a place where "timing out is OK", I'd find somewhere else where it isn't, because I think it isn't OK. At all.
(And in addition to that, the basic premise is clearly flawed because it gives a person who is losing a way out without taking the consequences of losing. That is just obviously wrong.)
(There are of course reasonable circumstances for timing out, like a health or natural disaster - a change of circumstance you couldn't predict. That's what moderators are for - I was more referring to "normal" course of events)