They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.
In the free software world, the Franklin quote could be rewritten as "They who give up essential freedom to obtain a little convenicene, deserve neither liberty not convenience".
Is it ever OK to give up an essential freedom? I belive it is.
For example, I am OK to use the Google search engine, even though it is an evil, non-free service. For the moments I use it, I give up a little bit of my freedom. However, I am not bound to it: I am not committing myself to using the Google search engine forever. (I wish there was a free alternative that was useful.)
This is an important distinction from, say, using Microsoft Windows. If I were to start using Windows, I would quickly have to invest a lot of time, effort, and money to buy, install, and learn a bunch of evil, non-free, proprietary tools. These form a network effect that results in making it very difficult to switch away from Windows.
For example, all my documents would be written in Microsoft Word, and all my e-mail would be in Microsoft Outlook. All my photographs and their metadata would be in Adobe Lightroom. And so on.
It is possible to break free from that jail, but it again takes a lot of time, effort, and possibly money.