Exactly this. There's plenty of legitimate one-way uses of email communication.

When I'm getting confirmation emails from Amazon after having bought something, for example, I do not expect to be able to reply to the machine sending them out -- it doesn't make much sense.

I'll go further with my argument: the ability to reply via email doesn't guarantee my communication will be dealt with in an appropriate or timely manner. Far better, I think, to go to the support section of a site and use a guided process to get my query to either answer the question myself or to have it directed down the appropriate channel.

> the ability to reply via email doesn't guarantee my communication will be dealt with in an appropriate or timely manner.

If they're too incompetent to handle email, I won't expect timely or appropriate action from them no matter what I do, and I'll regard doing business with them accordingly.

Having a single email address at the top of an email, necessitating parsing or eyeballing the content to understand the intentions and then forwarding it on to the appropriate people is surely more work, and less efficient, than the alternatives.

It's conceptually easier to streamline support via a guided on-line process or knowledgebase type repository. Users can often answer their own questions, or if not they can at least be pointed at the appropriate department. I'd go as far as to say a large retailer would appear more incompetent if my only access to support was via a single email address.

I completely agree if the email was the only point of access, but forcing customers onto a site is a classic case of forcing customers into a work flow that makes sense for the organization instead of providing tools to work with the customer's natural work flow.