New Relic are an open source based company where they use a proprietary model, but I'm not sure they need to. Bringing the data and the analytical tools together is a key part of what they do, and there's a clear and obvious benefit to paying someone to improve the analytical tools available for already collected data. Effective data analysis is one of those bottomless wells where there is no such thing as "done" - there are always going to be new questions to ask, and new code to be written to answer them.
New Relic's enterprise offering is also New Relic hosted. As with Loggly, the storage management side of what they do is painful enough that it makes sense to pay to outsource it.
If they offered an encrypted S3 data export on an open source software base (ala Loggly), that would be a spectacularly low risk service at a very reasonable price. As it is, you have to allow for the fact that if New Relic shuts down, or raises their prices, you have no exit strategy (short of the "build your own metrics infrastructure").
However, the big difference between New Relic and a company like Atlassian is that New Relic don't make any claims to being anything other than a classic proprietary vendor. By contrast, it's hard to reconcile proprietary licensing with Atlassian's stated values.