NEW YORK ( TheStreet) -- For at least the last six years, it has been cool to hate on Yahoo!From the board of buffoons, to the turnstile of CEOs, the F-bombs of a sacked CEO, to the peanut butter manifesto, there has been endless fodder for funny tweets and blog posts. I'll never forget going in to meet a group of portfolio managers at one asset management firm last year discussing the case for buying Yahoo! "I can't get excited about Yahoo!," said one guy. "I don't use it anymore. Do you guys?," and he looked at his colleagues for confirmation. He hasn't been alone. If you back out the value of Yahoo!'s cash and stakes in Yahoo! Japan and Alibaba -- fully-taxed and at conservative valuations -- Yahoo!'s core business, despite being the second-largest site after Facebook ( FB) in terms of monthly users and larger than Facebook in revenues last year, is worth at most $4 billion. When I started to make the case for owning Yahoo!, I would hear "How can you own it with that board?" or "How can you own it with Yang?" Well, things have really changed in Sunnyvale and Marissa Mayer's hiring as CEO is just the latest proof point of that. The board -- including Jerry Yang -- is now completely reformulated as of this Spring. The old bozos like Roy Bostock are history. Jerry Yang, himself, now has left the company and the board. They have a CEO seen by many as a key cog in Google's ( GOOG) success over the past decade. Most people, including me, if you'd asked them last Friday would have said there was no way that Yahoo! would be able to woo Mayer away to Yahoo! One of the most popular topics of snickering about Yahoo! in the past has been its constant talent drain. With Mayer now in place as CEO, can you ever imagine having this kind of worry again at Yahoo! -- at least for the next three years? Yahoo! is suddenly cool again. Getting talent won't be a problem.
What will be necessary is articulating a vision for the company which suddenly gets investors to sit up and say "this stock shouldn't be trading at these levels." Mayer has the ability to sell her vision and get Wall Street to buy in. She has the tech pedigree and the communication skills. So, what is left to hate? The financials? Well, we'll see later Tuesday when they announce earnings, but Yahoo!'s likely to show its second quarter in a row of revenue stabilization after four years of declines. The irrelevance of the brand? Well, 700 million people a month beg to differ and the fact that Mayer decided to leave Google to join Yahoo! willingly says that she believes it's worth going to and not fleeing. And, as a follow-on point relating to the board: why would she sign up to be presided over by a board that was still filled with bozos? Her hiring is an all-clear sign to investors on many fronts. There are still challenges facing Yahoo! and Mayer in this new role. She's never led an organization before, obviously, and we've never seen her perform on so public a stage as she's about to. Yet, if anyone had told you before Yahoo! hired Carol Bartz or Scott Thompson, that Yahoo! had a chance to hire Mayer, you would have said they were crazy. This is a big deal for Yahoo! and its investors. At the time of publication, the author was long YHOO. This article is commentary by an independent contributor, separate from TheStreet's regular news coverage.