Even assuming your interpretation is correct, the claim is not that immortality would be boring. The claim is that nothing could be more boring than immortality. I would argue that an infinite series of observer-moments, each with a non-zero chance of being interesting, is ridiculously obviously less boring than a finite series of observer-moments concluding with ceasing to exist.
via.
Sounds like sour grapes. I'd heard of people holding such sentiments; this is the first time I've actually seen them expressed myself.