There's a big opportunity to solve this problem. I've always thought that a combination of expert reviews, combined with user reviews and those found on other reliable sources (Yelp, Amazon, etc) that were weighted via an algorithm could provide a more fair "review score" for products and services. Just like anything, the more data you get, the easier it is to provide a fair quantitative assessment.
It's not going to matter. Godaddy already has about 100x the external links that NameCheap does (according to SEOmoz[1] and Majestic SEO[2]). If NameCheap moved up, it was for reasons other than external links.
GoDaddy also has north of 50 million domains registered versus 3 million for Namecheap. If I understand correctly, GoDaddy doesn't make any (or very little) of domain sales, it's the other services like hosting, email, etc that generate the revenue.