I think the issue here is the language used. The research usually describes things in such a way that "rational = maximizing" and and the phenomena cataloged are "errors" or "biases" that make human behavior fall short of maximizing. So, you could easily come away with the impression that "irrational = always wrong" or "irrational = bad", but what is really meant is that "irrational = not maximizing".
Temporal discounting is just something we do. It's a heuristic[1] sometimes gives good results, sometimes doesn't. When it doesn't, the redditor suggests, that's what we call procrastination. When it works well, we generally don't even notice, because it seems so natural.
Procrastination often has no reward at all. If it has a reward, why call it procrastionation? You actually do something useful, if it has a reward.
That's setting a higher bar for "reward" than what is meant. Pleasurable activities like watching television or playing video games are "rewarding". That's why people do them. That's why people continue doing them even when they "have more important things to do". Yes, in the end, you might not get anything material out of them, but if it truly had "no reward at all", nobody would do them.
losing $100 might feel as bad, as winning $200 might feel good
That's known as "loss aversion", another cut from Kahneman & Tversky's Greatest Hits.
But if you think about that risk again for this point in time + one year it is not that unlikely anymore.
Notice that you say if you think about.... When people procrastinate, are they really thinking of those sorts of things. Suppose you're a student that has a paper due soon and opt to play video games instead. You'd probably be thinking something like "I'll play games now and do the paper later." rather than something like "I might die before the end of term, so why bother with the paper?"
That's not to say you're wrong: only to bring it back to the original context.
[1]: A heuristic, in other words, being a way of "avoiding cost" of doing the rational (maximizing) computation. So it's not really different from what you're saying.