A lot of websites that have a high PR on their homepage refuse to exchange links with websites with a lower PR because they think this is bad for their SEO. However, many of these website use a link page that has no PR or a very low PR. Unless they're doing homepage link exchanges. isn't exchanging links with high PR websites the same as exchange links with low PR sites?
Yep you're right, the page where your link will finally be posted will most probably be a PR0 with no back links apart from the navigations links from the same site (If you're lucky). Most probably the page will not be even indexed by google.
Either way Google PageRank is really a crappy way to determine who will and who won't be accepted to exchange links with you. I base my PR2 site on traffic, because I average 2000-3000 unique visitors per day - majority coming from Google - and it has been that way for a year or so. Higher PageRank sites don't exchange links with me because of my low PageRank, yet my search engine rankings are way better than theirs and so is my traffic and conversions..it doesn't make sense, but I guess people are too set on PageRank as the final factor, when it really doesn't mean anything.
Agree with you 100%, the only thing PR is good for is for selling links to other webmasters, it's practically easy to get some crappy PR3 site up and running and selling a couple of links of them for a couple bucks, not much but better than nothing.