Shouldn't the team manager be responsible for assigning other employees to assume and learn the duties of the guy moving on during his two week notice period? I think it's a bit unreasonable to expect help from the guy after that. The idea that you or your manager thinks it tarnishes his image for not doing so is a bit dickish, IMHO.
That the employees have to pay for their own water cooler tells you right there how much the company really cares and values you as employees. Of course they are going to abuse you and expect you to bail them out with email support after leaving the team.
I understand loyalty because what is good for the company is often good for the employee, but there is a point where the company stops repaying the loyalty and employees move on. I suspect your friend felt so. Making noise at work that he was unsatisfied with his job would probably have made his situation worse.
There are apparently some people who are still bitter about their bad experiences in their previous workplaces. You can tell because they get heated in discourse and it colors their responses. And I'm not saying the person quoted above is who I have in mind when I say that. I'm just quoting to respond to some things in their post.
The fact is, many, if not most people, have had bad experiences in a previous workplace. When that happens you are free to leave and move on, and you don't owe the previous workplace any residual support. Nothing wrong with that. You don't owe any loyalty to an employer who reserves the right to terminate you at any time. The old days of loyalty between employers and employees is, for the most part, no more, for better or for worse. But expectation of loyalty isn't the issue here (even though for some reason it was brought up by an earlier poster who somehow read things that way).
Nobody on the team expected the ex team member to continue providing residual support out of a sense of loyalty. And many team members, if not all, recognize that there are systemic problems within the department and team (which is part of why the ex team member left). And, yes, the manager's job is and should have been to make sure that a sound transition plan was well defined and tracked, so that important i's and T's would be dotted and crossed by the person's last day. It is a joint effort by the departing employee and manager. It's a management failure for not driving this. With that said, rather than an across the board lack of reply by the ex team member to queries by former team members (those that were on good terms and those that weren't, both) about projects left behind, email responses simply indicating no bandwidth to provide any residual support (even if the truth may be no will to provide it rather than a bandwidth issue) would have been the better action. It could even be a canned auto-response message. But by giving no replies, I think most professionals would not find that to be the best course of action. For one thing, you never know when you may end up working with an old coworker, customer, or manager (even if it's very unlikely you'll ever see them again). So, it seems to me that the best option would have been a brief one-time reply, even if canned. The decision to not reply to the former team's emails at all is the ex team member's choice to make. On the flip side, should there be a future need to reach former team members, manager, or customers by the ex team member, for some reason, or one of them ends up in a department that is of some assistance to the ex team member's department, there is potential for the lack of response by the ex team member to be reciprocated someday. Another reason to simply send a one-time response, even if canned, even if only to indicate lack of bandwidth to respond to former team queries, in a tactful and professional way.
As for the tarnishing of one's image, not paying one's share of dues owed after leaving does tarnish one's reputation. You can try to come up with all the justifications you want about why you won't make good on your debt, including how much you disliked your old workplace. But the fact is, nobody forces anyone to participate in a group buy. When you do join, you commit yourself to making good on the joint agreement.
And if anything is "dickish", it'd be stiffing your old team on a legitimate debt. Then again, some people are fine with defaulting on their mortgages or other loans. But there are some who see the ethical thing to do as paying what one owes, because they view their own character and integrity as being at stake. They can separate between their rightful debt/commitment made and their feelings about their former workplace. The size of the balance is irrelevant. Although unlikely, it may be possible some day for the ex team member to end up on the same team again with some former team members or former manager. And should that team choose to establish a group buy of their own, the default by the ex team member would potentially be taken to account, and there would likely be some hesitance in allowing the person to join, based on the past unresolved dues.