It's bad because I am breaking a skin track that makes travel much easier for other skiers. If it gets walked in, it generally negates that benefit, and once the track gets steep, the skins wont grip because there are friggin postholes. It really blows. And it turns out that there were several other skiers a ways behind me that day, who did end up using my track. Of course in powder it's not such a big deal, but in typical spring snow, where skis stay on top of crusts and hikers destroy the track, it sucks. It is generally expected that bootpackers make a bootpack, and skiers make a skin track, and that they stay separate.