Your Linux-example a) is by a long-term contributor having a bit of fun and b) is better quality than many of the spam commits in that it actually makes things a miniscule amount better. IMHO, actual typofixes in the scope of Hacktoberfest are okay - they help a tiny bit and they don't hurt much. If someone learns how to make actual PRs through that, fine by me.
compare e.g. clear spam, which adds a copy of someones website into the HTML specification repo: https://github.com/whatwg/html/pull/5972/files There is no scenario in which that is even a potential improvement.
