If you think you can do as robust a job at securing your mail as Google does with Gmail, by all means. But I'd feel awfully dumb if I migrated from Gmail to some other web mail provider only to lose my mail to a 17 year old with a Perl script.
If you think Google is the only company that can secure webmail, I bet you are an employee.
But anyways: what does it matter if your webmail provider isn't beholden to the government, if a suitably motivated teenager can read your mail because of software vulnerabilities?
Google Mail isn't likely to be more secure just because Google is inherently better at building software than anyone else. Rather, it's because they allocate more resources to the problem of keeping Google Mail secure than any other mail provider does (or even can) allocate to their security.
Second, the equivalence isn't false. The Venn diagram of sites that can be compromised by script kiddies is entirely contained by that of sites that can be compromised by NSA.
Please do tell which one? And why you are sure they are not beholden to a government?