Maybe it's just me, but I read the argument as being fairly consistent i.e.:-

The product is still in beta.

Indicitive of the product being in beta, the following issues arise:- :-

Managing a mailing list isn't trivial. Trying to send legitimate attachments with executable files is damn near impossible. Even ZIP files are a chore.

When will these issues be fixed, who knows?

When they are Gmail will probably no longer be a beta.

In my opinion, as a simple web mail system Gmail is fine, no better, no worse than most on the market.