Earlier quoted context omitted.
I think that is the worst reason for them to rewrite titles. If they left the title as-is, then I would be able to see in the search results that it was a spammy site and ignore it. Instead Google is helping to launder their SEO and present it as a more legitimate site. If Google thinks a site is gaming their algorithms they should de-prioritize it, not rewrite it.
"Gaming their algorithm" sounds like a fancy way of saying SEO. If Google can produce for me a more accurate (or concise) title, it should only help me find what I'm looking for. Forcing folks to trudge through inaccurate titles – or hoping people know the tells of a "spammy site" title – does not seem a better alternative.
That causes me to lose faith in google not a better experience.