Looks weired but a sound of C and T has to be somehow connected, at least it feels like they are to me. Based on my experience, sound of Polish Ć and Czech Ť are transitional between Polish/Czech T/C. Proper linguist might put some more light on it than just my speculation.
Even so clavicles can be asymmetrical due to previous injury. We are pretty asymmetrical overall if you look closely enough.
Those overly negative comments often come from USA. I’ve never had any major problems with self checkout in Europe and I generally go there as it’s faster and you don’t have to race against the cashier. Of course some chains have worse self checkouts, some have better but overall many people like it a lot. Even some older people who are not tech savvy use them.
Polish C is also described as /t͡s/ (e.g. co /t͡sɔ/). According to wiki both are dental and voiceless although one is plosive and the other affricate. As I’ve read their descriptions on wiki, they made a lot of sense - /t͡s/ starts with a blockade of airway (just as /t/) but the air is released slightly differently thus making the difference in sound produced.