I will show, in what I believe, the mistakes you make in the your counterargument:
1. You left out the verses that says the Qur'an is in Arabic, and that you must reason in approaching them, not simplicity (12:2, 49:3).
2. Qataa doesn't simply mean 'to cut' in Arabic, the meaning is derived through context in any conversation. If we follow your simplistic approach to Arabic, then qataal-lisan would literally mean to cut your tongue off instead of 'shut your mouth'. If we only had that one verse, then you had a point, since we then could not deduce a clear context. But since we do have other verses, we can follow the rules of context:
As the Qur'an says we must look for things beneficial for mankind (13:17) and use a compensation system (11:114) and be fair in our judgement and not be harsh (5:8).
3. The verse says aydiyahuma which is the plural (three or more) of yad (hand) used in dual form. As humans only 2 hands, this would create a contradiction, or we must suggest thiefs must only be punished when working in groups. Even if we accept that the hands refer to the hands of both thieves, should we then cut off both hands of a thief? That person would then become mostly useless for society and would be a burden for a small village or a larger society. We cannot cut off 1 hand, as we would then not follow the Qur'anic injunction.
Thus it is more logical the thief must compensate for the theft, by not only returning the stolen goods, but also by doing labor that would compensate as a punishment and a way to redeem him/herself for that society. The labor would cut off the means of further thievery as the person is in custody. This is possible in every little village in the world, as slavery was also possible in every little village in the world.
4. This is also suggested in the story of Joseph where he let his brother to be arrested for theft. He doesn't cut off the hands of his brother, but it is suggested by the other brothers that he must compensate for the harm. In 12:75 they say the brother belongs now to Joseph. Through the trick Joseph circumvened the law of the Pharoah (12:76). And this punishment for theft is called the law that Abraham also followed (12:38) and that in this story there is a lesson for us (12:7).
5. Almost every person who could speak Arabic whom I discussed this agreed with me. These included academics but also simple village people from Morocco or Kurdistan. I myself also am only a student, not a professor. I only learned Arabic 2 years ago and am still learning. But after some simple reflection on some other verses and an easy reference to some dictionaries, and I could deduce this conclusion. It is a simple conclusion when one uses reason and context.
6. The problem lies also in our current education system. Most Muslim countries who are not native Arabic speakers are not taught Arabic as a second language. If we follow your 'simplicity' rule that this would not possible for simple villagers, then please explain to me why it is possible to teach children to recite the Qur'an in even the most simple village everywhere in the Muslim world, but it is to difficult to also teach them the meanings of Arabic? We of course then, as a second step, must also teach reflection and reason, which are the biggest obstacles in the Muslim world.
As you can see, we deduced a far more logical conlusion not by writing pages and pages of tafsir, but by just 1 single post. That is simplicity for you...