Otherwise, I totally agree with your statement here. Especially considering that your employer is not likely to be up-front with you when business gets bad (at least, not right away), you can wind up with the "corporate blinders" on and not notice the signs around you that your stock is about to tank. I've only worked for three different companies at this point in my career, but the quarterly "business group communications meetings" always felt much more like pep rallies than real status updates, meant primarily to boost morale rather than to inform. In this day and age, to place trust or loyalty in your employer is to misplace it, as employers are highly unlikely to place either of those things in their employees.
What I'm trying to say is: your logic here is sound, and your strategy is a good one, but be careful about ignoring corporate politics.
Often times I have "sold to cover" which is to say exercised the option, and immediately sold enough of the stock to cover the cost of exercising the option and paying the tax. At that point you have shares in your company in your brokerage account where the "basis" is the fair market price when you exercised them. A year and a day later (to convert to long term gains) I've sold half the shares.
When my RSUs at Google vested they would automatically sell some to pay my tax obligation, but I would instruct them to sell half as well. Same philosophy. Get some of the money diversified, keep a bit of skin in the game in case it had a gain.
There is no difference (except for a few bucks in broker transaction costs) between doing this and selling ALL of your RSUs as they vest ie "auto-sale" and buying Google shares on the open market.
Although the latter emphasizes the decision you are making to concentrate on a single issue rather than diversify.
Being long on your employer just seems like a really stupid idea. I don't consider myself likely to be fired for incompetence and I'm not high enough on the ladder to be fired for political reasons. If my income stream ever goes away, chances are it'll be because my employer stock is doing the same.