Not sure what you mean. It's not pseudoscience or shady. Still, that's the problem! It's probably physically possible, but we're not making much scientific progress towards making it happen.

When I mention cryonics people tend to respond very negatively without engaging rationally. More so than with most anything else. It's sad that it's something you can't say even here on hn. http://www.paulgraham.com/say.html