Of course it seems economical and efficient to attach the switch directly to the board, however...
Do you intend for the switch to be exposed? Suppose a user were to press the switch with all his might? Suppose the switch is facing down if he drops the unit? Does the force bend the board? Does it fracture traces? Loosen components?
Sometimes repairability is preferable over durability. A flexible attachment might be preferable. Such as short lengths of 20 gauge wire. Then it's:
* Easy to test the switch in each assembled project
* Easy to install the project in the enclosure.
* Easy to push the switch snugly up to the opening (thin wires bend easily).
* Easy to clip away a bad switch.
* Easy to test a replacement switch.