By the time your LiPolymer battery is unusable, You will be using a completely different style of Player with much much higher capacity.
Much is made of the non removabilty of the battery. You can buy an e200 or c200 series player if you want a removable LiOn battery.
To make the battery removable adds thickness and adds cost to the player. It also introduces another connector which can fail.
Todays LiPolymer batteries are so much more durable than they used to be. Its really not worth the costs to make the battery removable anymore.
