Quite frankly the people who care about locked bootloaders are few. Like you that would be the reason I would not buy. But the reality is there just is not enough for manufacturers to waste time caring about that. Especially when developer and Google play versions failed to sell. We had our chance to prove to manufacturers that we cared about that stuff a few years ago and the market responded by proving the oems right that not enough people care. In fact even among those that care about unlocked bootloaders we failed to show with our wallets that they matter. When it is all said and done the old saying stands that money talks....... walks.
So other than nexus devices do not expect manufacturers to waste their energy worrying about bootloaders as they know that factor has a negligible effect on sells.
Great. I would hope they would show themselves not worrying about them by not locking them.