I was about to rage as soon as I red the news but quickly came back to my senses after realizing that its actually a good thing. Let me explain; Free Steam accounts and by free I mean zero purchases are mostly a ghost town or used to spam. It is very unlikely that a spammer or troll will put any money toward creating trouble. The paying customer will not notice a thing provided he spent $5 or more.

Official Restrictions:

Sending friend invites
• Opening group chat
• Voting on Greenlight, Steam Reviews and Workshop items
• Participating in the Steam Market
• Posting frequently in the Steam Discussions
• Gaining Steam Profile Levels (Locked to level 0) and Trading Cards
• Submitting content on the Steam Workshop
• Posting in an item’s Steam Workshop Discussions
• Accessing the Steam Web API
• Using browser and mobile chat

I can however see this becoming a problem for the following users:

CD Keys, retail purchases, and gifts do not remove limited user restrictions even if they significantly exceed the required quota.

What if the persons uses retail keys? Why should any paying account gets restricted? I feel the above will be removed or at least less restricted with time but for anything else this seems like a fair deal.