Did you ever see upvotes before the downvotes? If not, then those might very well be pity upvotes to balance the downvotes, as downvoting without any explanation might be considered unwelcoming?
In general, I'm not feeling sorry for those who simply do not care to read about the site they're trying to get help from. Not at all. But as off-topic questions are posted on Meta's quite a lot, I indeed always figured that many people were simply lost, like you wrote. But even more: I've always wondered how many ended up on Meta's by following links from some "How to ask", so possibly actually trying to understand how things work. (Good!) Or maybe somehow got lost after following some link after signing up? (Your two examples are not new users on the main sites, but I think posting off-topic questions happens to new users a lot too.)
Also, once lost, the help they get on Meta is not really telling them they took the wrong turn. The weird requirement for the tags, "must include at least on of (bug feature-request discussion support)" might be the most explicit warning. The yellow "How to Ask" box might not be explicit enough: I feel it's not necessarily clear that "Is your question about the Stack Exchange engine that powers the Stack Exchange network?" is actually a requirement:
So, I often wonder if all the blame is on the users, or if onboarding or links in the help fail them too. For such cases, I could understand that some might cast a pity upvote.
I wonder if SE ever investigated the logs to see why so many people end up asking on Meta's. (Like: how often are off-topic questions posted, what path did the users follow, how many are posted by new users, how many users have been question-banned.)