Ha ha, nobody is forcing you to buy it my man...
I kind of like to be able to choose a new fresh band when upgrading - often times my old watch is being sold with a band attached, so I will end up with as many in the collection as before.
For me it's even good, I have a collection of 16 watch bands today. I really enjoy changing them regularly to match them with my clothes. The great thing is retro-compatibility. It's great that watch bands from first Apple Watch are still compatible with latests models.