What motivations to go Points-based do they have besides baseless worries?
I suppose I should make an amendment to my rant: Base your dislike of Steam on facts and opinions, NOT fallacies or irrational suppositions.
What motivations do they have? Money, greed, the same thing that motivates other companies to do things to screw over customers. You have assumed I don't like Steam, but you are wrong. If I dislike Steam so much, why have I bought over 40 games from them? I like Steam, and that is why the introduction of this wallet worries me. Ask yourself this, why did they need to implement this Steam Wallet service if you can put just what you need in it for a purchase? The http://store.steampowered.com/subscriber_agreement/ (that thing you have to agree to, but never read) pretty much tells you of their motivation:
Funds added to the Steam Wallet are non-refundable and non-transferable. Steam Wallet funds have no value outside Steam and can only be used to purchase Subscriptions and related content via Steam (including but not limited to games offered on the Steam Store). To the maximum extent permitted by applicable law, Steam Wallet funds that are deemed abandoned or unused by law will not be returned or restored.
When your account uses your Steam Wallet to fund a purchase, you authorize Valve to deduct the amount of the purchase from your Steam Wallet. If you do not have sufficient funds in your Steam Wallet to make a purchase and you have previously entered your credit card information, we may automatically charge your credit card a minimum amount determined by Valve to make the purchase, even if such minimum amount exceeds the cost of your purchase. Any difference between the minimum charge and the cost of the purchase will be credited to your Steam Wallet.
Any funds you put in your wallet can only be used to buy things from Steam, they can not be withdrawn. They want to get your money in their wallet so you have to use it at their store. Currently on the http://store.steampowered.com/steamaccount/addfunds/, you can only add funds of $5, $10, $25, $50 and $100. They may not call it "Steam points," but the concept is the same, to make you add funds to your wallet in fixed amounts that are more than what it costs to make a purchase so your leftover funds are stuck there. Yes, they
currently still let you make purchases with credit/debit cards and PayPal, and I hope I am wrong but this could be the first step to gently get people onto a "point" type system.
You say "base your dislike of Steam on facts and opinions, NOT fallacies or irrational suppositions." I say don't let your unconditional love for Steam blind you into thinking that they would never do anything to "gyp" their customers.