As a former (self thought) electronic circuit designer I can assure building electronics from scratch is not an easy task and finding the right IC for the application is usually the most challenging part of it.
If you take the time to go to Digikey.com and do a simple search for “dc motor driver” will find it returns thousands of IC candidates, you will then have to read endless datasheet pages before sorting out the ones that might suit your project better and start ordering samples, buy IC clips or make custom PCBs just to be able to connect to them, next the testing begins, custom coding and more testing until you find exactly what you need, is a long and tedious process you need to go through, multiple iterations and more and more testing because the last thing you want is to come up with a flawed product and face a big recall.
I do agree with @jonatpridesleap in the sense that anyone is free to copy, work, learn or build on top of any open source project they like, is a personal decision to contribute back or not, but the original creators MUST be credited which is the missing part here.
Also doing a simple “TB6643” forums search yield to this old post that you probably missed too.