Disclaimer: I was a DAO investor. The DAO held 5% of my Ether at the time of the attack.
Having said that, it's not as simple as saying: I support the DAO refund because it was in my best interest. That doesn't necessarily follow, and it didn't necessarily follow for most of the other DAO investors.
I still held 95% of my crypto $ in Ether. I would have been happy to eat the 5% loss if it would have been the right thing to do and instilled confidence in Ethereum and its leadership. There were many debates at that time about what the right course of action was, and it was a very hard decision. If saving 5% of my investment meant I ended up with a worthless 100%, it would be foolish to save that 5%. And everyone else knew this as well.
I think the decision the Ethereum team made was the best moral and legally advisable choice. They had the opportunity to stop the theft of 14% of all Ether, which would have gone to a criminal actor. It required a very risky solution (a hard fork) which came with big consequences (an alternative chain which remains to this day), so the solution wouldn't be feasible for smaller attacks (as some people like the poster before you try to allege). But for an attack which threatened 14% of the available supply, a hard fork to retrieve the funds was a viable solution.
Most of the market agrees with this decision. In the time since the Ether market cap has grown to the second largest of any cryptocurrency at 1/2 the size of Bitcoin. The alternative chain that didn't fork is still alive but only has less than 10% of the Ether market cap. The vast majority of dApps are running on the Ether chain. And it's the chain that is being taken seriously by enterprise (look up "Enterprise Ethereum Alliance"). Large businesses know the founders can't simply hard fork whenever they want to better themselves. The model works around consensus, consensus that is clearly shown by the considerations listed above, and I am glad that the consensus model is strong enough withstand an attack on 14% of its supply and respond with a difficult solution to rescue the chain from a catastrophe. It makes me feel more confidence in the technology, the community, and the protocol.