[kleiba]

Tons of people started using gmail exactly because of the user interface.

For your second point, if you really mean "locked in" (as in "my company has outsourced their email to gmail") you can always use an IMAP client.

But I guess this is just a small typo and you mean "logged in" - in which case I'm not sure I can follow? Is your point that people don't like the user interface but use it anyway because their friends use it?! Not sure I buy. If no-one forces you to use gmail, don't use it. Or, again, use an IMAP client.

[rhnoble]

Not to mention keyboard shortcuts! Navigating with my keyboard seriously saves me tons of time everyday.

[kellishaver]

Also very handy for users who can't see the mouse well or rely on a screen reader.