I've learnt about the concept of donation matching only recently (it's not used all over the world yet). It doesn't seem very honest to me. And not only to me, e.g. http://blog.givewell.org/2011/12/15/why-you-shouldnt-let-don...
There's absolutely nothing inherent to the concept such that it's dishonest.
It exists to drive others to get involved. It's an excellent mechanism and works very well by getting attention and encouraging people that their contributions will be magnified. It's a deal: you give, I give. There's nothing dishonest about that.
Further, the donor in this case is matching an 'unlimited' sum. There's no artificial cut-off.
And then I realized "ah, because then I wouldn't have donated my money."
It's not totally honest, but I get why they do it and I don't regret donating the money so in the end, whatever.