Estimates have it that there are about 50k people being paid to write Ruby on Rails right now, chances are that it's way higher because it starts to be the language of choice in outsource India because of the high conceptional similarity between different projects written in rails and how they help new teams get started with an existing code base.

I sure as heck can't find enough people to hire for ruby ( and even objective-j !!) jobs.

I'm not saying your figure is wrong but I think that if you actively look for a job in these languages then it's pretty simple to find one.