Steam friends limit

So I have been interested in the xp and trading card system when it was released through steam. While reading up on what it was all about I noticed this, 

If your Steam Level increases, the limit on the size of your friends list will be increased by five, and potentially you'll unlock the ability to customize your profile with showcases.

why must they limit the number of people you are friends with? what if you are someone who only likes to play one game all the time on steam and never really wants to buy new games, plus has many friends. Im sure there are many people who dont want to be involved with the trading cards or xp, and their experience is being limited by the new system. 

I know this doesnt really apply to myself because i will never fill up my friends list, but it just doesnt seem right to limit a feature like a friends list. What are your thoughts?
 

(also, to gain xp to expand your friends list you have to either be a member for a certain number of years, spend an amount of money on steam, or craft the new badges with trading crads. I think there are someother ways, but these are the main.)