Language is a set of tools. In the same way it can be annoying to watch someone hammer in a nail with the end of a wrench, it can be annoying to watch someone sort through their linguistic toolset, ignore the finely-honed implement meant for the job and grab another.

But when you're writing something down (especially for publication), you can not know your entire audience. Not using reasonable care in your written language communicates exactly that: that you care not for your audience.

Or that you care for a specific audience. I, for one, do not care about any audience members who get up in arms if I use "begs the question" in the sense of "raises the question", for example. The use has become so common, that I expect anyone who finds that offensive will not be worth the trouble for me to try to cater to.

You need to draw a line somewhere, or you will end up spending your life obsessing over unimportant details of what you write instead of actually communicating.

If your omission of what you assume is "unimportant detail" leads to your audience misunderstanding the "important" detail, you actually are failing to communicate.

It may also happen that the one person who you felt was not "worth the trouble" turns out to be someone who will be very important to you one day, like a potential business partner or investor, and who interprets your misuse of language as ignorance.

There's a difference between obsessing over unimportant detail and being thorough, IMHO.

Well your right their.

You think you're being cute, but if spoken aloud, there is no difference. It's only for historical reasons that homophones have different spellings.

If someone posts a link to correct you, there is at least one person put off by your language.

Oh absolutely; the ethos of one's argument could be greatly damaged with something like:

OMG u shuld see wat they do in germanny its so different their!

But at some point you do start to get diminishing returns, so there are practical limits to how worried one should be about pedants.