Cosmology is a field that has a lot of gaps in current theories (one might even use the term "gaping chasms"). Because of this, alternative theories are more readily accepted and considered than other fields, simply because there's more conjecture and less evidence to support the current popular best guesses. The last hundred-or-so years have certainly seen a couple of massive overhauls in our understanding of spacetime, who's to say another isn't just around the corner?
It's not like we're talking about alternatives to evolution here (I use evolution because it's another theory the public has a poor comprehension of but has overwhelming evidence and demonstrated predictive power - far more so than String theory and Big Bang, even). We've made massive leaps in our understanding in the last couple of decades, but are on far less solid ground in relative terms. That's not to say we're wrong, but a good scientist will always consider well thought-out alternatives.
As for Electric Universe and its Plasma Cosmology though, isn't that like 50 years old now? There still aren't many taking it seriously. Trust me, lots of very clever people have probably read this by now, and if it was really an avenue worth exploration then I suspect we would be doing so already. Those of us who are mere laymen may not understand the reasons for particular theories being rejected by mainstream science, but I tend to trust cosmologists most of all when it comes to thinking outside the box on stuff like this.
I think ultimately this gets filed on the shelf next to the Expanding Earth theory.
