It absolutely does not need to imply anything about the psychology behind the position. If I'm long BTC (or whatever) it simply means I'm holding a position that benefits from a positive price movement in that asset.

The more pop culture meaning of 'long' meaning "i support" is post facto the other pre existing meaning. And it's not unreasonable to correlate them. If your money is where your mouth is, they are the same thing.

It's totally possible though to be "long BTC" via a position while thinking bitcoin is a total scam, if let's say you believe you can exploit some short term irrationality.