I wouldn't call "Welcome to..." passages silly or unprofessional. I would call them valueless to the user. There are better ways of introducing your content.
Jakob Nielsen addressed this very issue some 7 years ago in "Blah-Blah Text: Keep, Cut, or Kill?":
The worst kind of blah-blah has no function; it's pure filler — platitudes, such as "Welcome to our site, we hope you will find our new and improved design helpful."
Kill the welcome mat and cut to the chase.
However, it doesn't mean that all useless text needs to be removed. Nielsen warns against leaving pages without context in the process of cutting down the copy. He recommends keeping the absolute minimum needed to answer the question: What's the page about?
In a more recent article "The Fold Manifesto: Why the Page Fold Still Matters", Amy Schade of Nielsen Norman Group touched upon not only on users' scrolling habits but also on how to encourage them to explore the site and the content:
Webpages need to build a solid story. Users can be encouraged to scroll by giving them good reason to do so. Visual elements can draw the eye down the page. Compelling content can draw the user in. If the most interesting information is at the top of the page, users may be enticed to visit the bottom of the page as well.
There are certainly designs that successfully offer very little at the top of the page while enticing users to scroll. Successful designs encourage the extra effort —they offer a glimpse of interesting content, a compelling introduction, engaging imagery.
The translation of these recommendations into your own copy depends on the purpose of your site. If it's simply an informational site, write some bold and compelling headlines or taglines. If it's an e-commerce site, calls to action and marketing copy will do the trick.