Was it the task itself you feel was disrespectful or the way they ran it? Anyone can put up fake/inflated CV so it's not really proof they didn't bother to read it, GitHub can be easier or harder to fake/inflate depending on the projects. Doing something like a quick palindrome checker to show "Hey, yep - I'm real not some random inflated applicant you probably got 10 applications of alongside mine" seems more than reasonable/respectful (by both sides). I can also easily see how 5 people can hop on and completely run that task in the wrong way and come off as being know it all douchebags or the like but that'd be a different independent issue really.