I seldom reply. The articles are disguised ads. Its so poorly written or full of grammatical errors that it is obviously not of value. It is not an interesting subject nor done in a compelling manner.
Poor writing is poor writing.
Remember in many circles, unsolicited email is called spam. If I don't ask for your submission - then I owe you nothing. You're the one who wants something - otherwise you wouldn't be writing it for free. So - you can be upset that editors don't respond to your writing or you can be pleased that an editor did. I've browsed some of the so-called free business writing available on the Net in my capacity as a contributing writer for a business magazine.