I'll start off with a lil scenario, that maybe serves as an analogy to some current on-goings...
Imagine you work in a technical field. In most technical fields, they have certifications. Officially recognized industry organizations set the standard baseline of skills and knowledge for any specific area of subject matter. Screening for the certification is typically in the form of a multiple-choice test. If you want the certification, you pay a monetary fee, take the test, and when you pass, you now have a new title on your resume. It is not uncommon for an employer to pay the fee for an employee to take certification exams, or even pay for training that will prepare an employee in the subject matter.
Companies are happy to pay for the training and certification process. The company benefits from having a more proficient workforce, and the employee benefits from having additional skills, and the pride that comes with achievement.
One thing you'll often see in technical workplaces is that shortly after a person gets a new certification, they generally look for a new job, maybe with their current employer or not. If the career move is internal to the firm that paid for the training and examination, then it is regarded as a win-win situation for both parties. If the employee leaves to go work for another company, their former employer tends to feel used.
So, this isn't a Java blog, its a WoW blog. So what's the point?
Well, in WoW, we don't have an officially recognized industry organization that sets the standard for skills and knowledge, but we do have the Armory. Armory establishes the baseline of your stats and also specifies bosses that your toon is guaranteed to have killed.
Also in WoW, we don't have companies that pay for training to prepare an employee in subject matter. We have guilds. Guilds that accept "uncertified" players, who's Armory stats are in need of help. Guilds help their players "train", via Heroics, helping farm mats for craftables or enchants, and raids.
Players take certification exams when they fight bosses that drop Tier pieces. Tier pieces become soulbound to your toon, you log out, and instantly, the Armory bestows upon you a new level of certification.
And, on either side of the analogy, its not uncommon for people with new titles, or new T4 sets, to go looking for new employers, or guilds.
I just never expected it to happen so fast.
How's this for a timeline:
Invite Player to Guild
Run Player Through Heroics
Run Player Through Karazhan
Progress with Player Through Early Zul'Aman
Progress with Player Through Gruul's Lair
Elapsed Time: 3 Months
Reward T4 Loot.
Receive Whisper "we gotta talk, im out"
Player is Member of #2 Guild on Server
Elapsed time: 18 Hours
Whether it happens in the workplace or in WoW, it leaves the people who helped train you, gear you up, with a sour taste in their mouth.
In the end, you gotta do what you gotta do, I let go of my spite, I wish you the best of luck, and focus my efforts on gearing up your replacement.