Tinkering with designs

After the fight that almost developed regarding UHU's designs it got me thinking, as the forum knows I tend to tinker with allot of designs that are uploaded on this and various other sites to improve the designs (well in my opinion anyway) and I have always been careful to obtain consent from the original designer before doing so.



So here is my question, if a design is uploaded on here and another user decides he can tinker with and improve it is there any reason why he shouldn't do so even without the consent of the original designer?



As long as the design is improved and the original designer is acknowledged is there any harm in doing that and should the original designer be offended? If it improves the design where is the harm?



Thoughts anyone?