Ideas are a dime a dozen, however, it is likely that usage of jailbreaks were useful evidence about which features are so desperately wanted by people that they are willing to go through a nontrivial inconvenience just to get them.

Customers saying "I really want X" is generally just empty words with poor correlation about how much X is wanted, and you should take that with a grain of salt instead of assume that there's a demand for X; but on the other hand if there's a price attached (either a literal payment, or price of inconvenience as in this case) then seeing if customers really want this is very useful data.