This situation reminds me of Movies.SE and "identify this movie" requests. Here, it's always going to cause heartache to close questions about the Chinese language off-topic on a site about the Chinese language. It makes me feel we should avoid it if we can.
I have a rather intermediate attitude towards this.
Cons to allowing such posts:
The site wouldn't be of much interest if the majority of questions were "what does this say?" "what does that say?"
We don't want the site to turn into a bulk translation service.
These questions are of minor (if any) academic interest, and limited future interest.
In short, it's quality control. (It's also an issue for me that Imgur is blocked in China, so I get nothing from these questions.)
We're not in real danger of being swamped by such questions currently, but it is a future concern.
You've demonstrated in your answers that they can have some value beyond simply "it says ABCD".
By answering the questions, we circumvent the arguments and disruption caused by closing posts. Indeed, we don't really have enough active users casting close votes, so answers appear before closure anyway.
My experience is that "first post = worst post" on StackExchange, so I advocate leniency towards new users, which is where these questions mostly come from. (But it seems many of these users don't return, so this is not a strong point.)
It's not at all easy to envisage a means of inputting Chinese writing (especially if you've never done it before). In fact, particularly for seals, I'm not sure I'd even be able to figure out a way to convert it to a computer format. (Also, this information could be included in an answer.)
They might be useful for giving new users an opportunity to write answers.
In short, they're questions about the Chinese language and we want to be welcoming.
I've seen too many disputes over "you didn't show effort" (PSQs) over at math.SE. I feel there's a reasonable argument either way. It wasn't until math.SE encountered a large numbers of effortless questions that everyone got together and said "nah, this has to change".
Temporarily allow these questions until we feel they are becoming too much for the site. It's so much simpler to just answer them and move on.
And changing the title afterwards to include the answer seems like a good approach to resolving: What can we do about the useless titles of "what does this say?" translation questions?
I also encourage upvoting questions you'd like to see more of at the site, to make sure that users see the kind of content we're looking for specifically.
It might also be worth thinking about tagging them consistently, so people who don't like them can ignore the tags.