It’s easy to cast off grammar as if it were a quaint vestige of some prim and proper era — a form of good manners or etiquette, like using the right fork. But without grammar, we lose the agreed-upon standards about what means what. We lose the ability to communicate when respondents are not actually in the same room speaking to one another. Without grammar, we lose the precision required to be effective and purposeful in writing.
Yes, this is important. Unlike the grunt of pleasure or pain one might express in the moment, written language endures over time.