I also experienced the same thing.
I will never deal with Walmart for anything mobile phone related other than buying a SIM card, assuming they would sell me one.
Walmart Markville Mall in Markham didn't let me buy a SIM without an activation either.
If the mobile kiosk people are just third-party sales contractors it doesn't really surprise me that this is such a widespread problem.
I am a new customer of Public Mobile (only 2 weeks)... So I thought I would get a friend to switch over - Went to Walmart to purchase a SIM card and was told they can't sell them anymore without activation? I don't want a Walmart employee to create a profile for me - to ask me my address - to ask me my phone number - to ask me my email address. I don't want to stand there at the Walmart computer and scroll through a large list of phone numbers to find one I like. Why the new policy and a third party relaying my personal information?? The other 2 places that your SIMs are available would be at least a 90 minute drive (one way) for me. I changed to Public Mobile - Don't start disappointing me!
The guy at the Walmart I went to let me use the computer all on my own, not sure if it was because he was busy with another customer, but I liked the fact that I got to enter all my data without his help, give a referral, enter my cc number, etc...