Probably because all the wallets have their own timeline to implement it. And it’s so easy for the user to just keep everything the same.

I remember the crazy amount of Fear mongering and how the slow adoption scared most people off.

With the years of discussions and reviews by some of the most brilliant people it was apparent to be a success. I even took some serious time looking in to what it did.

Probably one of the best moves ever moving to Segwit