Without a good platform there's not much to say about the validity of a programming language for a specific task other than it's Turing complete and it has features that might be nice someday if they could actually be used.
Until Rails ruby wasn't a particularly nice language for coding server-side web applications. In 2002-2003 I worked for a company developing one, and had it taken off we would have had to rework it in another language very quickly.
What $foo web frameworks were people using before Rails?
Until Rails, people mostly wrote CGI-style applications.
(Yes, there was mod_perl, which people mostly used to make their framework-less web apps run a little faster; and there were Java MVC frameworks. Those were the exception, though, not the rule. Most people just wrote CGI scripts.)
Iowa and Cerise were running production apps before Rails. Nitro came out at the same time as Rails. (There may be more, but I'd have to go look it up. They're described in The Ruby Way 2nd ed.)
Rolling your own request-handler+template thing is not hard. Nor is using DBI. Having stuff all bundled up is a big win, but it's not something essential. Ruby's a clean, fun language.
"Until Rails, people mostly wrote CGI-style applications."
Well, maybe that was prevalent with Ruby (whose mod_ruby is/was iffy), but mod_php was damn near everywhere before Rails.
Until Rails ruby wasn't a particularly nice language for coding server-side web applications. In 2002-2003 I worked for a company developing one, and had it taken off we would have had to rework it in another language very quickly.