Spam? Hardly, it's a chance to try out games for free for a couple days. If you don't want to download it nobody forces you to.
If someone sends me unwanted mail with an URL in it for some game, then nobody is forcing me too also. Still, it's spam.
The same goes here: in the All Games map there is suddenly this unwanted game to try for free. For me, that is pure simple spam.
Definition of spam by Spamhaus: "An electronic message is "spam" if (A) the recipient's personal identity and context are irrelevant because the message is equally applicable to many other potential recipients; AND (

the recipient has not verifiably granted deliberate, explicit, and still-revocable permission for it to be sent."
I only have Skyrim that is connected with Steam. I do not have anything else to do with it, I never asked for "free games" nor gave permission to give/send links to me. If it is mentioned in the Steam user notes that these kind of things will be send, then that is not valid because I have no choice: if I want to play Skyrim, I HAVE to install Steam so I HAVE to accept their "rules". Sure, there is the offline mode. But I have to go online with it for updates. And there is nowhere something in the Steam app where I can say "Do not send me totally irrelevant messages, I am not interested in Steam at all". So again, for me it has all the marks of spam.
Yes, I am one of many many people who don't want that Steam thing but are forced to use it. If Steam was just an app to validate software to counter software piracy, fine. I would have no problem at all with that.
But it's not: it's acting like it's some highly critical part of the game, it's acting like an app to promote Steam and games. I will not use the crack to run Skyrim without Steam ... but I can fully understand all those people who are using that crack.