Assuming you still disagree, I'd be curious about your opinion of non design issues. Do you think samba is bullshit for having reverse engineered the CIFS interface allowing non windows computers to share on corporate lans? How about various office applications that reverse engineered the file formats of various closed competitors to allow them to save and load the formats? Surely a lot of hard work went into designing CIFS or .xls, should that be off limits as well? If not, why is the location of buttons on a screen a bigger deal than the locations of bytes in a filehandle?
But, as in all things, there is a balance, and one can go too far. What the developers of MobileRSS did is not wrong because they copied, it is wrong because they only copied, and didn't make it better. They didn't incorporate good ideas from Reeder into their own, making something new and beautiful, but rather substituted Silvio's ideas for their own which is lazy and the opposite of good work. I know whose future development I want to support.