Do you want respect from your readers? Do you think you should respect your readers? If you read a book or article, I have no doubt you are gratified to see that it's written in an understandable, consistently formatted, and grammatically acceptable (if not completely correct) manner. You don't have to write like that, but people will respect you and feel as if you respect them if you write this way. 
(I'd like to reference people who care about the issue of content quality and respect to read my other, newer article [1] on the subject.) 
Most blog places, this one included, have a "Preview" option (it's pretty much required, here!). So, no one should go ahead and post their blog without correcting the formatting and grammar and spelling a little.
As a writer, I'm inclined to say it's simple. It might not be, but this is what I wish would happen:
1. Everyone should use paragraphs, instead of one big, long, gigantic entry that's all together and isn't divided up and seems to go on and on and on and on forever and ever amen just like this sentence that I'm sure you're sick of reading by now.
[Edit after a few comments have been made: Paragraphs, bulleted points, numbering, or any kind of system to help indicate separation of ideas -- these are all helpful. If you write one long paragraph, but use words such as "First", "Second", "Then", and "However", that really helps with reading. However, I still advocate the use of paragraphs.] 
2.  Everyone should support their claims with factual information and/or specific examples. Academic publications, like chemistry magazines, prefer that scientists back up their claims with experimental data. If it's something that people know is debatable (e.g. how many people have died in Iraq so far), people should cite their sources (e.g. which newspaper) they got it from. If it's something obvious, like "Followers of Jesus are generally considered Christian", then maybe it's not so necessary.
3. Everyone please punctuate your sentences properly It is a little strange when people don't punctuate Sometimes I think it is hard to follow when people don't use periods or use, commas in the wrong place Therefore please consider helping me out by ; putting !! punctuation marks in appropriate spots because if you're here you probably passed elementary school grammar 
4. DON'T USE ALL CAPITAL LETTERS WHEN WRITING YOUR ENTRIES. THIS DRIVES EVERYONE CRAZY. IF I READ AN ARTICLE BY SOMEONE WHO DOES THAT, I WILL AUTOMATICALLY ASSOCIATE THEM WITH MY MOTHER, BECAUSE I WILL FEEL LIKE THE AUTHOR IS YELLING AT ME!!!!!!!!!!!!!!!!!!!! (PLEASE DON'T USE TOO MANY !!!'s EITHER!!)
5. Your entry should not consist mostly of quotes. "Yesterday in Baghdad this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this and this happened." Oh and here's what I think about it in two sentences.
6. Finally, please let there be a point to your argument. Butterflies are really pretty, and so are bees and flies and spiders and flowers and women and booze. As a matter of fact, you should state your point somewhere in your article, and make it clear that that is your point. I like chocolate a lot, I bet I like it more than you do, and that's all I have to say about that.