If you have anything Android, Tasker has near-unlimited functionality. If you're tech-literate, you could learn the programmable syntax and I'm sure you could trigger that event.

Not to mention there are alarm apps that take RSS feeds to radio/playlists/podcasts, I wouldn't be surprised if there were a Youtube alarm app already.

iOS is a very locked-down operating system. As a result, you can't interact with the hardware and trigger time-sensitive events, or open applications without the user's permissions. Every application has its own environment, which (for security reasons) isn't able to be "breached" by other applications, even if it's intentional. It's good for older people and tech-dummies - so they don't run a malicious application that gets access to their other applications (banking, facebook, contacts). I buy Android because I know what I'm doing and I can do tons of cool things with it as a result.

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Alternatively, you can do BIOS-level configurations on a PC that will allow it to wake, auto login, and open a browser to a specific Youtube video on startup. It may be a ~2-5 minute delay with boot time, but again, can't do that on Apple hardware.