I saw a lot of posts on the DX clusters (basically, a system where hams can announce to their fellow hams that they've contacted, or at least heard, a particular station on a particular frequency; there is also some capability to post single-line comments) that complained about the TX5C guys. Mostly, they seemed to be complaining about how they weren't working some area of the world at the right time, or about how they weren't working their favorite band, or mode, or whatever. Later, I saw complaints that the on-line logs weren't updated instantly after they left the island. (Keep in mind that to do so not only requires a satellite uplink, which they have, but also a stable platform. A small boat is not always a stable platform.)
I have never been on a DXpedtion myself (I don't really count my week as ZF2DK as a DXpedition) so my comments here are based on what I've learned from others whose opinions I respect. One thing that is pretty obvious to me is that these DXpeditions are costly, require a great deal of planning, time, personal committment, and can be quite dangerous. As an example, Bob, N6OX broke his ankle within a few hours of landing at Clipperton on the TX5C dxpedition. Others have been injured on trips, or even worse. These folks are quite literally putting their lives on the line to provide enjoyment for their fellow hams.
Others have said that "if you don't like the way they are doing things, get off your couch, cough up tens of thousands of dollars of your own money, spend a week or two in a burning hot/freezing cold/soaking wet tent, and do the operation yourself". I heartily agree.
While I will admit to being occasionally frustrated, particularly early on, when TX5C seemed to start to work Europe just as 40m got really, really strong to my location, I'd just grumble quietly to myself for about two seconds while I thought about what I wrote about above, and just move on to doing something else. I did not waste my time posting rude comments to the clusters. Many of those were apparently done using someone else's callsign, presumably because the complainers chose to hide behind the relative anonymity of the DX clusters (and the Internet) rather than be brave enough to use their real callsign.
The fact is that while those guys (and gals!) on Clipperton were doing the best job they could (why would anyone do anything else?) others were saying some pretty awful things about them. Why? To what purpose? None of the people saying those things were on Clipperton, they don't know what the conditions were like. Perhaps some of those complaining were part of the problem. Steve, K6SGH, posted a wonderful update detailing some of what went on during the operation. He said, in part:
We would have made a lot more European contacts, especially in hard paths, if European operators would be more courteous and stand by when they are told to stand by. Instead, almost universally, they continue to call on top of each other while we are attempting to working them. It's frustrating for us and deprives others of making contacts. Most operators are more respectful and stand by when told to do so. Operating styles may be diverse, but courtesy should be a universal concept. We all are, after all, members of the same hobby. I have seen on the clusters negative comments by some EU calls that we weren't working them. From my perspective, they need to consider their own behaviors before they start ranting about us.(By the way, I highly recommend reading that entire post, there's a lot of great stuff in there.)
For myself, while I certainly would have loved to have worked them on many more bands, I did make contact on 3 bands, on both CW and SSB (no RTTY, unfortunately), I thought they did a great job. For radio, it's all in the Ear Of The Beholder.