Fonts aren't used merely to ensure good appearance of a design, they have the power to express emotions. There are particular features in fonts that are perceived as "funny", "serious", "majestic" etc. Fonts, holding such power, are an invaluable tool commonly engaged in the process of designing websites and web applications.
In our era, many websites are meant to be co-created by its users and, as such, consist mainly of user-submitted content. Web designers often decide to force a sophisticated, emotion-inducing typeface on those parts of an application that are generated by the community.
I think that a user's post or message displayed with a particular font bears an extra message, an implied emotion not originating from the user themselves. Sometimes that emotion might even conflict with the core message. While I have no trouble discerning the message from the way it is displayed to me, I feel somewhat uneasy about the discord.
There are many generic, regularly-shaped fonts (both serif and sans-serif) clearly designed for the sole purpose of presentation of content. Common examples (as viewed by myself) include Arial and Times New Roman, but apart from those iconic typefaces, there exist many more similar in features.
A short comparison of UX.SE and Christianity.SE: the former seems to go with Arial, then Helvetica, and assumes a system-default sans-serif font if the two are unavailable. I consider this to be a great design choice for a community-generated website, as it is mostly up to the user how they present themselves. On the other hand, the latter of the sites has a sophisticated way of displaying textual content. The typeface looks fancy and remains consistent across the entire site, but reading user content presented in such a way induces certain unnamed emotions in my mind, distracting me from the content itself.
It might just be my supersensitive nature, but I am certain I'm not the only person to perceive the Web in such a way.
Should web designers present user-generated content in a way that is emotion-neutral?
Is there any convention or research regarding the matter?