So you're more or less in a dilemma between choosing to hold your coins and benefit yourself financially, or help a business and contribute to the Bitcoin ecosystem but with less financial gains potentially.
I say do what your heart tells you. If you think that selling the bitcoin is too much of a wrongdoing to yourself, then don't. If you think that the business, the people you'll get to meet and work with --the ethical satisfaction in general-- outweigh the capital appreciation over the long term, then you gotta sell.
I share a similar opinion, however I want to add something to this too, and that is a reminder of the kind of world that we live in.
I'll start with a similar example.
If you have only $100, maybe giving $10 to a homeless person is not the most responsible situation for yourself. Sure, you are doing good and helping another, and maybe it will come back around in the future if you are a believer that what goes around comes around...but immediately, is it wise? Why not work until you have $1000, or $10000, and instead give more, with more comfort and security?
The same goes for you OP. If you hold 1 BTC and the business you are seeking to support will cost you 0.1 BTC, maybe it's not the wisest decision. That doesn't mean you still can't support them with a lower amount however, say, with 0.001-0.01 BTC.
If you hold 10 BTC, maybe 0.1 BTC is an appropriate contribution to the bitcoin economy, and it will be an investment that won't hurt if they don't succeed.
Short answer - If you are fixed on contributing to adoption, then maybe it's wise to just invest a fraction of your holdings rather than a chunk