Yes. Formal language doesn't really matter in an informal setting like an internet forum, but it does matter if you can't even be bothered to make any attempt to use English roughly correctly and it matters that your attitude is common. Human language needs to be able to convery human levels of thought. Reducing it below those levels reduces how much people can think. Read about Newspeak in 1984.
+1. Sorry, but just because people are typing posts on an internet forum doesn't excuse laxity in any form of orthography. Spelling, grammar, punctuation - all of these things should be second nature to you, unless English isn't your first language or you have a learning disability. I can understand that language evolves over time, but resorting to the half-arsed standard of forum-posting displayed by the majority (less here than elsewhere - go figure) isn't evolution, it's devolution. One of my biggest fears is that society is not developing now on the grounds of what's best for all, but on what's most popular, and to be honest, what's most popular is 'The Sun'- and 'The X Factor'-style mentalities, fatuous expatriation on the virtues that have enabled our species to refine on the unprecendented opportunity Darwinian natural selection has bestowed upon us. I don't recall bull**** bastardisation of language being included in the right to free speech, either.