Totally agree, but it's not just the SSPCA. A friend of mine was looking to adopt an abandoned Basset from the breed rescue a few years back and was told that she wouldn't be considered if there were likely to be days when the dog would be left on its own for more than 90 minutes! Utterly ridiculous.
That being said, I can see why in certain circumstances, with dogs that have particular issues, it might be necessary, but not as a blanket, cover all policy.