If I work my butt off training for a race, but for some reason on race day I just don't have it (whether it's a mental issue, physical issue, or just poor timing with picture/character stops) and I get swept, I'm still going to feel a sense of accomplishment. Medal or no medal. I put in the hard work, and even if my race day performance doesn't reflect that hard work, I believe that sticking to a training plan and working hard is an accomplishment.
Of course, I speak only for myself here, I'm not saying that everyone who gets swept will feel a sense of accomplishment. Just saying that I'm offended that you think that someone who gets swept automatically has no right to feel a sense of accomplishment. For many people, making it through training and showing up on race day is a huge accomplishment.
Whether or not that accomplishment should be acknowledged with a medal is a different question. But "finish" and "accomplishment" are not synonyms, and I wish people wouldn't use them as synonyms.