To be fair he wanted his money back after near 300 hours of play time.
To be fair, he probably backed based on marketing and other information released by CIG, promoting the game as some sort of wonderful playable thing, with disclaimer in small print, yadda yadda, nobody ever reads, which is why some countries have ruled ToS to be unenforceable. Maybe he backed when Chris was stating the game would require a bit more polish and be released in a couple of years or whatever.
So he played, thinking that (based on CIG's own statements) that the game would get better, that it would be really playable and in a releasable state.
And after some time, he came to understand, it was all a load of horse manure, that they had been misled, lied to.
I think that's fair enough grounds to seek a refund.
What matters is whether the law of the specific country agrees in such situations.
Its been suggested before that sooner or later, someone or a group are going to successfully challenge CIG in court for non-delivery based on their marketing, Chris' statements, and other promotional materials, and the court will throw out CIG's disclaimers based on the marketing and promises, and it will set case law, opening the floodgates for refunds.
Whether this will happen remains to be seen, but we've already seen kickstarters cause a number of legal cases and in some countries the lawmakers are starting to take notice.
Look at what happened to Shroud of the Avatar and Chronicles of Elyria. Both only managed to stave off lawsuits by keeping the games under development by a single developer. Gariott got lucky and found someone to take over while he disassociated himself from the project. Christian (CoE) as i understand it, is basically now sole developer. Both games promised the ultimate games of their genre, both failed badly. Time will tell with SC, but for the moment, its only the funding that is keeping it alive.
What happens if those funding the game start to realize that the emperor has no clothes? Funding drys up and CIG downscale. Considering they are adding new stuff at a snail's pace with over 1000 employees, how will development look when they have to downscale to 500, or 100, or 10, or... 1?
I've asked faithful before, who claim SC is already the best space game ever, how many people they thought would continue to play SC if development stopped today? No new content ever. Would it still be considered the best space game ever? Or is it all fuelled by dreams of the game it one day could be, if CIG ever get their shtick together?
And if funding did stop and development eventually did, we can look right now and clearly understand there is no way CIG are releasing anything approximate to what CIG sold to backers before the money runs out. They probably couldn't even squeeze out a half-baked SQ42.
That would open the floodgates to refund demands... but there would be no money left in the bank to pay those refunds, even if the courts decided in favour of the refundians. Well, except for the IP to Star Citizen, that Chris sold to CIG for a few million... maybe the refundians could take joint ownership for that and sell it to the remaining faithful backers for a few million

The only money that wouldn't have been spent would be nicely tied up in the bank accounts and trusts of Chris, Erin, Sandi, and Ortwin.... not much, just a few tens of millions perhaps.