This is quite odd?
There are three kinds of business people.
1. hmmm... now I know -- I'll just do it myself.
2. Eyes glaze over on hearing we'll add keywords..., and
3. I don't have the time... I got a business to run.
So while you are protecting so-called "trade secrets" from #1, so you can do it for them, and know full well that your so-called "trade secrets" are protected with group #2,
That third group (and the most profitable I might add) you'll never reach and therefore is left for those that demonstrate... qualified knowledge, skill-sets, and credibility for a long term relationship.
In addition... if and when group #1 fails due to limited overall knowledge, they are more apt to return to the consultant that was most forthcoming, and a second crack at the relationship.
As for Google... Their interest is protecting the quality and integrity of the index... if no spam tactics are used and quality website information is pushed forward -- do you really believe Google will change from this so SEM(O) can't make a living. Google can adjust the algo as much as they want -- you can't lose! ;)