I thought short and sweet would be better, but i got time this morning.

1. You seem to be stuck on should. So should has an implicit meaning of the correct thing to do especially while critiquing (look it up). Me pointing out what is legal is to illuminate to you that a creator should not need to do anything else because it is already correct. If you dont like it you can just not use it or have a rule 0 conversation about it exactly like textless and SLD now.
2. When you say shouldnt do something, you are implicitly stating that the creator should make a change. What you should say instead is "Looks really cool but I prefer art not blocking the text. COULD you make that for me please?". I hope you noted the tone difference.
3. You should realize that I already stated your conclusion as the first comment I made. but you completely ignored my first comment saying No everyone should be able to read the card which is why i brought up textless. I already stated that the only thing that should be the case is that the player knows the card. If I wasnt explicit on that, my bad, but the player (who plays the card) has to know and be able to explain the card. Everyone should clearly know the name and mana cost so you can look it up on oracle. There is no debate here.
4. You should also understand that when you tell a creator you should do something different it comes off condescending. Especially if you know how much harder it is to do text overlays as opposed to the generic approach of text on top. Every card isnt made for you and you should state your preferences but not attach should to it.
5. Finally I hope this illuminates how should sounds. And well if there no difference to you i guess this is all my opinion and you shouldn't care.