The only vaguely plausible rationale I could conceive of for your ridiculous assumption that all client-side javascript engineers would have server-side experience was an underlying assumption that any job in client-side javascript engineering would involve server-side responsibilities.
Evidently this wasn't your actual reason for thinking that, which just leaves me even more bewildered by your position.
Evidently this wasn't your actual reason for thinking that, which just leaves me even more bewildered by your position.