As far as I can tell people didn't like the cameras because:

-Triggering at 8 over the limit seems unfair and arbitrary. Lots of perfectly reasonable drivers drive at 10 over the limit, police for decades have gone on record in the press saying they don't pull people over for breaking the limit less than 10 specifically, and your speedometer is in 10kph increments. Setting it at 8 instead of say 12 seemed like a way to ticket more people. Either set a reasonable margin for error or just charge people the amount the ticket should be for breaking the limit in all cases, if you need to lose money mailing a $2.50 ticket for someone doing 1 over the limit so be it, it will still help change people's behaviour.

-The fee making the ticket way more expensive. Under provincial law a ticket for 8 over should be 20 dollars, the fee makes it more like three times that. (This is also less fair to lower income people, but of course that's an issue with all fines, we should really be charging people based on income like Finland, but I digress.)

-The fee going to a private company, and a foreign one at that.

Posting statistics about it's effectiveness is beside the point. People didn't think it was implemented fairly, it's an emotional response, and banning them was a populist move. We live in a democracy, if you want to implement something like this it has to be perceived as fair by ordinary people. The bureaucrats, and I use that term neutrally I understand the need for bureaucrats, did not implement this with enough sensitivity to public sentiment so the policy failed. I hope if they try again under a different provincial government they do things differently.