If you can't keep your talent as an employer, that's your fault. Berating them for taking care of themselves is immature. Welcome to capitalism, you make money off them and they're free to take the best offer on the table.
As an employer, I prefer have people with many job experiences - so when they show up here they can tell they're respected and fairly compensated!
I "hopped" my first 3 jobs because my employers seemed bound & determined to wreck their companies, and me with them.
It's not MY fault that they were too gutless to fire the "expert" who spent his whole day nagging me for help, and who used raise_error() as GOTO. And who earned $15k/yr more than me, I knew, thanks to the H1-B notice posted in the kitchen.
It's not MY fault they joked about how this client (MY client) was a sociopath who called people and ranted at them at 3am, and then expected me to give him my cell phone number.
It's not MY fault that my boss had a tantrum in a meeting, screamed at people, then busted up a printer in a rage.
It's not MY fault that the CEO constantly derailed our projects and everybody stuck around only because of the golden handcuffs, but I was tired of being demoralized and feeling like I wasn't earning my pay.
I did my best for every employer I ever had, and they never did the same for me. To the contrary.
Maybe he just doesn't want to hire job-hoppers because they have a sense of self-respect.
I understand as an employer you'll want someone who, when you get into a rage and bust up a printer, won't quit and head for greener pastures. It may seem an exaggeration, but as we both know, these things actually happen and while this might not be what the original author had in mind, many, many places of employment are awash in insanity. When you are young and just getting a start, it's easy to miss the warning signs in the interview or just have less options.
Job hopping in response to that might just reveal quick growth in skill, leading to better alternatives. It is a competition both ways. That guy that job hops a lot, maybe he can do that _despite_ a resume showing what employers consider disadvantageous, because his or her expertise is clear in interviews. Almost by definition, job hoppers are more in demand.
The ultimate goal of an employer should be to attract and retain the best employees. It is true that retaining is easier if you decide to exclusively pick from people who didn't have better options when their jobs suck, but personally, I'd rather have someone like you who left when the scene got crazy. Maybe that's just because it so closely reflects my experiences. (In fact, I think we shared an employer)