I've read some of the history on the Generalist badge in these questions:
The arguments were made pretty well for a gold level version of Generalist (Polymath, Polyglot or Sage defined it like "Provided non-wiki answers of 75 total score in 20 of top 40 tags") in those questions and I would add the following:
The definition of a gold badge:
Gold badges recognize important contributions from members of the community. They are rarely awarded.
The definition of a silver badge:
Silver badges are less common than bronze ones. You'll need to plan your strategy to get one of these.
After the Generalist tag has been around for ~4 years it has only a little over 500 people achieving it on SO. It's relatively difficult to achieve and as a silver badge says "You'll need to plan your strategy" to achieve it. You can make a pretty decent case that Generalist is one of the most difficult (if not the most) Silver badges to achieve as well as being good for the site.
A gold version of Generalist would re-encourage the ~500 users who achieved a score of 15 in 20 of 40 top tags. Specifically this refers to those that just scored 15 in certain tags and moved on, it would give them incentive to go back and visit those tags more often if there were a gold badge to be earned.
Based on the responses in the two threads I posted, it seemed like people think there should be a badge like this, it just didn't seem like there was a consensus on the details back then.
My suggestion would be altering the definition to try and best balance difficulty of achievement and value to the community. Something like this:
Provided non-wiki answers of 50 total score in 20 of top 40 tags
Another possibility to add would be a requirement like "having at least 2 silver tag badges".
So the actual question is: If there was a gold version of Generalist, what should it look like and why?
To clarify my read of the situation: It appears the community has decided the original designation of Generalist as a silver badge is acceptable(explicitly by making it Silver originally some what implicitly by leaving it). My example is proposing that the gold version would be set with an equally high bar. The question I am asking is that what it should look like, why or why not?