I think so, but that's also really great because I frequently run into the five hour caps, but very rarely use my entire weekly allotment. There are lots of situations where I do things like write the plan for all the work that has to get done, and then set a reminder to execute the plan after I get home, when I'm done making dinner (because e.g. my five hour cap ends at 6pm). Higher caps for the five hour period is a lot more convenient.
The purpose is to control the total amount of requests they need to handle in a given timeframe. If everyone could use up their whole weekly limit in 5 hours, many would do so, thus pushing the GPU/TPU clusters to or above their capacity limits.