1. Jerseys or shorts that don't have enough pockets
2. Jerseys or shorts that don't have big enough pockets
3. Jerseys or shorts that don't have enough zippered pockets
4. Jerseys or shorts that have pockets that gape open too much (not secure enough pockets)

The only reason I will buy a bike jersey at all (rather than just a regular fitness shirt) is that it presumably offers good pockets. I know pockets are rare in bike shorts but I will often wear triathlon shorts that do have them. Easier to reach for the shorts pockets than the jersey pockets.