Since social media positions are a relatively new career path, and in fact a relatively new online platform, many people just don't understand it at all, especially the older generations. I find myself as a social media professional constantly explaining myself to those that aren't as well-versed in this industry, which I'm happy to educate those that are less aware, but the below statements will make any social media managers skill crawl.
I don't really see the point of social media.
Welcome to 2014. If you still don't see the point of social media, then you're living in the past my friend. Google some case studies on how social media has made an impact on businesses, the community, the world, and how it has completely changed the way ourselves, and consumers interact and communicate. Then tell me you don't see the point in it. Still not convinced? Watch this video.
What do you even do all day?
Oh I just sit back and stare at the computer screen. Seriously? What do you do all day? A Social Media or Community Manager has a set list of responsibilities just like anyone else does in their position. From monitoring your online community, to offering customer service, to developing and seeking out content to share and interact with your community with. Customer has a complaint? They're going to social media! Customer has a question? They're going to social media. Customer has a compliment? They're going to social media. Get it?
People pay you for that? My kids could do that. 
Yes, your kids are on social media, in fact everyone's on social media, meaning your target market is PROBABLY on social media, so yes, they do pay me for that! Need I really say more?
Make it viral.
Asking me to make everything go viral is like planning for a national news story. You can't! No one can plan for their content to go viral, and be shared across everyone in the online world. All you can do is plan your content to be share-able, engaging, and original and hope that it catches on. So asking me to make it viral is like asking the IT guy to hack on to everyone's computer in the world, or the finance person to "find" $1,000,000 hidden amongst your finances.
What happens when social media isn't a thing anymore? 
What happens when an accountant isn't a thing anymore? The world is constantly evolving, and no ones positions are guaranteed. Yes you may think that certain positions are ALWAYS going to be needed, but once upon a time people used to think the only way to book a trip was through a travel agent, now look how technology has changed that. The reality is, with technological advancements we have no idea where any position will be in the future. We may all be replaced with robots for all we know, so stop only pinpointing social media jobs.