You're right. They do have intrinsic value because they have inherent labour to produce. You could also argue that those who have been participating in the community and holding them for many years contribute added value to it. In other words, the storage of bitcoins is also labour as is the storage of gold for example, which requires securing.
Unfortunately, in terms of seizing the means of production. You could also argue that as well, that is, the means to produce more money.
However, it does not constitute seizing the means of production in society as a whole. The factories, transportation and the big companies continue to be held in the hands of capitalists and bitcoin cannot touch them.
It is also true that Bitcoin takes away the capitalists capacity to direct monetary policy and to produce fictitious capital in the form of loans. However, by piggy backing other projects that can produce loans, that is enabling precisely that kind of capital. The only way to literally take away the means of production from the hands of capitalists would be to develop and enforce more elements of exchange in society through smart contracts. So yes, cryptocurrency is very compatible with socialism. But as long as society continues to concentrate private property in the hands of a small minority, society is nowhere near socialism.