Once or twice a month perhaps not ... but the 10-ride users only start to gain if they have 21 or more trips in a calendar month! That means you means that if you could do a return trip on GO as frequently as every other business day and still be paying more than using a 10-ride trip.
The mistake is making the base price, the cash fare, rather than the the discounted fare. I'm not aware of any other system where you pay the full cash fare by using this type of card; compare to London Underground where a single cash fare (zone 1) is £4.00 compared to a single fare on a card of £1.60 (no monthly minimums).
The pricing seems reasonable for pass users, but is a complete failure for other users. Which reinforces that GO is more interested in peak-hour commuter service than trying to provide a proper transport network across the GTA.