It makes sense that Cinnamon is given more attention. It is the Mint team's baby, after all.
I think the real problem is that new users who want to give Mint a go aren't given enough info on the differences.
Looking at the Mint 15 release announcement
, or going to the Mint 15 Cinnamon download page
, it's never mentioned that Cinnamon isn't suitable for old PCs or that it's more resource-heavy than MATE, the prominent alternative offered. The same system requirements are listed for each.
It may not be a problem for users who already know what they're after and why, or for those with compatible hardware, but for anyone else, they may end up with a horrible first impression of Mint because they chose a desktop environment not suited to their setup.
Not to get off-topic, but I think the bigger issue is that there's too much emphasis on the "latest and greatest".
It's good for users who are used to or don't mind reinstalling every 6-9 months, but for users coming over from Windows or OSX, who presumably don't know what an LTS release is, being told they'd need to reinstall after 9 months in order to receive updates is a turn-off at best.