Personally, I do like using a credit card for everything, makes for a simple bill, everything summarized, easy to track expenses, paid automatically too. Completely hassle free. And of course that comes at a cost.
However, I've always felt like a business should be able offer a lower cost if paying cash. By that not being legal, you're forcing everyone to pay for a service you're not even using when you pay by cash. Does not seem right to me.
On the other hand, businesses will be losing 3% on cash transactions. And cash can also be a hassle for a business too. Gotta count it, secure it, deposit it, keep enough on hand, etc, and now the business will be asked by certain customers to give up the 3% CC fee in order to take cash. If I were a business I'd say, "sorry, cash has its own overhead costs too". Most businesses thrilled by this announcement are the ones who are hiding transactions from CRA.
I could probably save $300/mo on average if I paid everything in cash instead of credit card. So would I give up the convenience of a CC for saving some cash? Hmm. Good question. Cash is a hassle, always running to the bank for more. I would certainly switch some bills from automatically going to a CC every month to be a direct debit from my bank account. I guess I like having that choice.
CRA is probably not too motivated to give people any more incentive to use cash though. Big brother likes to be able to audit you and see where your money comes and goes from.
It will be interesting to see if this amounts to any significant change at all. I kinda predict not, at least for most people and most businesses.