I don’t know what the intent was, but I think it’s a way of thinking about the feature that makes it much more appealing. Instead of a Hail Mary with a 90% chance of failing (which feels pretty close to useless), thinking of it as a solid chance that with a week or so of asking for your god’s aid every day, they will eventually step in and help you out in some significant way, feels much more valuable.
I also don’t think of it as limited to the effects of a Cleric spell. Sure, that’s listed as an example of what kinds of effects might be appropriate, but I think of it very much like Wish; if you just pray for a resurrection, then the DM knows that’s appropriate to grant with no strings attached. If you pray to protect an area from danger, the DM can look to the Cleric spell list and say, “well, Hallow seems to fit the bill.” If you pray to smite the BBEG of the campaign, the DM probably isn’t going to just have that happen automatically, but they might use fiat to give you some major boon that will help against them. It’s all ultimately up to DM judgment, and the cleric spell list serves as a source of inspiration for the DM to inform what benefits they might grant.