Some people are telling me that homepage link exchanges are a bad idea and that you should stay away from it. Yet I've seen so many successful websites using this practice. What is your idea on this?

Link out to what makes sense to link out to. Exchange, no exchange, it really doesn't matter. Just link out to what makes sense to link out to.

What are you basing "success rating" on?

Jut put nofollow and you will be fine with exchange from home page

Some of the reasons you were advised against it are

1. Link exchanges are aimed at getting you more respec from search engines. They're usually singular in purpose. Most people who engage in them care about nothing else, and so tend to sacrifice the user experience. Adam hinted at this - link out to what helps your users, and they'll come back to visit your site again.
2. Outgoing links for no reason are tacky. When you see a bunch of them along the bottom or side of a page that aren't connected to the rest of the design, or are totally unrelated, it feels like web browsing at KMart.
3. A home page is the most tacky spot you could put quid pro quo links. Blogs are a little different tho because all pages are your home page and your home page is every page.

keep a limit of point links from homepage. If you are point some best sites but not more than 4 or 5 its ok.

...and the reason for that is?

Originally Posted by kalseo

Jut put nofollow and you will be fine with exchange from home page

lol, I do the opposite. I put rel="vote-for" to indicate content that is worth reading.

Homepage link exchanges are not bad. they seem to be quite helpful to my site.

Homepage link exchanges are not bad but 4 or 5 links it’s ok.

Link exchange on homepage is not bad if its relevant and not too much. Moreover 3 way is good!

The whole idea of "link exchange" must always be dealt with carefully. Keep any links found on your index page to a minimum and only the most relevant to your site content.

The practice of "mass exchange" just for the sake of building inbound links could hurt you in the long run.

Some site owners place a simple directory on thier site for the express purpose of link exchange. I have not seen that this will cause any harm but I have also not seen that it has actually been much help either.

Bottom line, oly exchange links with other sites that have highly relevant content and keep the number of outbound links on your individual pages to a minimum.