You are free to read only those posts whose language you understand.

Yes, just as you can "just press delete" when you get a nasty piece of spam in your inbox. This defense has been widely used (and widely disporoved every time). However, it is fundamentally wrong to force content down the throat of your users.

That out of the way, here are some half-cooked thoughts...

English is not my first language, spanish is. However, we have to deal with the fact that (for now at least) english is the technical lingua franca on the Internet.

People writing software in Perl need to have at least a rudimentary knowledge of english, as most documentation exists in that language. Would the lack of this restriction increase the audience for this site and perhaps Perl in general? Likely, yes. However, your proposal does not seem to bode well with the way in which this site is run.

Go back and take a look at some (already lengthy) posts (for example, this tutorial of mine).Now imagine what keeping things in sync between versions in two languages, would mean... I know it, because I run two sites that are essentially bilingual, and that is very tiresome. In the long run I believe authors would simply reduce their posting or do so in only one language.