It's difficult for the reasons stated by the author. You have to convince an employer to sponsor your H1 befor you even start working for them. Also, they need to apply for your visa and hope it comes through before you start work.
Why is the first comment always negative? The author of the link wrote an article based on his experience. I find that every first comment on HN is a tear down of the original post. The tone of every top comment seems to want to prove the com mentor's genius over the author.