Funny I was referring to /keyword and I didn't post my absolute agreement with your statement, because I didn't notice it until I came back and re-read again later... I don't like it either. Saw it happen for the first time the other day (to /keyword) and thought 'How tacky?'.
I can understand why Status_203 would want to use it, but from a visitor and site owner perspective I found it odd at best and didn't like it much... Also, as a site owner, I wanted to view and link to the home page of the site, not some keyword inner page.
If it was /home or /index or even /overview I would have simply linked to the root and let people get redirected, but /keyword basically 'screams' built for search engines to me, personally. (I can't think of any other reason to redirect to /keyword... It's Status_203's underlying reason IMO, because their site might grow, but it's really not, again, IMO as much for visitors as it is for future ranking purposes. No offense intended Status_203)
I actually almost didn't add the site to the directory I was building at all because of it and finally decided to add it so if I decide to remove it from displaying it's already in the DB and no one else will be able to add it back in.
It will most likely be removed from the 'main' listings section where all the home pages are listed, because it makes my directory look 'odd' to have one site with the /page-name on the directory page where all the other sites listed are domain name only, so I guess the short version is: If they want to have an inner page as a home page, then they can live with being listed with individual page listings rather than with all the other domain names.
I'm not sure if it would have any 'super positive' effect on rankings (I really can't see how it would, but this isn't one I'm going to test personally), and IMO it has a definite negative effect on visitor experience. Mine any way. Can you imagine what someone who doesn't know the web might think? Where's the home page? Why can't I look at it? I keep deleting this word and my browser keeps putting it back in... What's going on? Not really the site I want to send visitors to.
It's not even like the page is called /home or /index so people can understand 'Oh, this is the home page...' It's /keyword!