Smalltalk had design mistakes aplenty. Comparing the downsides of the languages you like less with the upsides of the languages you like more is not a great way to understand why things are done the way they're done. Usually, it's not because people chose the worse options, but because each option has pros and cons, and at the time a choice is made, the chosen option's balance of pros and cons was more suitable to people's needs than the alternatives.

It may sometimes be the case that we say, oh, that particular feature of some unchosen language can be very useful for us now, but that is something very different from we should have chosen that other language - with all its pros and cons - back then.