My goodness, it's been a long time since I last posted!
The leads on the switches need to be long enough to get "pinched" by the metal contacts down inside the breadboard. If they are still arched, they may make enough contact to work electrically but may not be long enough to stay in place. The funny shape of the leads is intended to keep the switch in place during automated assembly and soldering.
Look at the third picture down in this Adafruit article about breadboards. Component leads pushed into the breadboard are "pinched" by the metal clips with enough force that you should be able to pick the breadboard up using a LED as a handle. The plastic housing of the breadboard acts as a guide and insulator and has little to no effect on retaining components.
You can straighten the switch leads by using a small pair of pliers or tweezers to squeeze them flat but they are so soft that you can also use your fingernails to flatten them. Just don't flex them back and forth too much, they will break off. It's not the end of the world if they do, replacements are cheap or short wires can be soldered on to repair them.