I think it'd be nice if the community did contribute more towards the servers. More money in general equals better servers. In the past I haven't really been interested in other people paying towards my servers, but I haven't played much lately so it might be a good idea to move towards that. The hardware running the EU servers is pretty old and could do with an upgrade, which wouldn't be particularly expensive.
If the US servers are really as bad as people are saying, then something certainly needs to be done about them.
There's a few issues that need to be resolved first though:
1) You need to confirm that you'll have enough every month to pay for any servers that you host.
Enthusiasm over these new servers won't last forever. Some people will stop playing TF2, some people will have circumstances where they can't pay anymore. It's important that funding levels for servers are maintained.
To host a tempus server, it's most likely that the "TF2 server hosts" like multiplay just won't work. Tempus has a lot of custom plugins and may require installation of new software on the server. Instead, you'd probably need a VPS or dedicated server. I wouldn't recommend VPS as they can have reliability problems, which you're trying to get away from in the first place. A dedicated server will only have one user, so it's better for reliability, but modern hardware is pretty overkill for a single TF2 server. If you rent a dedicated server, you could probably host 4 TF2 servers or more on the same box.
As a ballpark figure, my current server costs ~£32/month ($47/month). Keep in mind that though I have one physical dedicated server, all three EU tempus servers are hosted on that. I'm not familiar with pricing for dedicated servers other than my host, but I think my host is pretty cheap compared to the rest. I'd suggest that if you wanted a dedicated server on the East and West coasts, you'd need at least $100/month. Though again, these would give you four TF2 servers each.
2) You need someone you trust to handle the renting and setup of the servers, as well as the crowdfunding.
The people who handle the servers and the crowdfunding don't need to be the same, but the more people involved, the more complicated it gets. Ideally you'd want to have someone already involved in tempus handling all of this, but it's a fair amount of work and responsibility, so it'd be better if someone volunteered for it.
3) You need to agree where you're going to host any servers you have the money for.
No single server site is going to please everyone. I don't even think a full network is going to please everyone. Different places in the US will have different server costs, as will different hosts. I think it'd be a good idea to confirm with people whether they're paying towards a specific server, or tempus as a whole. If someone in the community is an expert on hosting servers, their input here would be very helpful.
4) You need to have a system that handles all of this in a transparent and simple way.
I think it's important for crowdfunding like this to be clear about how much money is needed, how much is being spent and where. It's also important that the hosts have a good idea on how much income they'll have in a given month. I think Patreon handles a lot of this, though I've never used it.
5) Approval from Rob123 and jayess, as well as any other involved admins.
Overall, it's a nice idea but it needs a fair bit of thought before it can become reality. If the community can agree on all of those issues, then I have no problem with this going ahead.