I guess I'm just desensitized to this. It's a pretty normal thing in a lot of large and influential churches. I've seen it done regularly at Lifechurch, North Point, Elevation...just off the top of my head.
I kinda see it as the thought of there are a lot of people who aren't used to giving. And who think the church is only after their money. Something like this could be used as a step to help people start regularly giving to the church for a set period of time...with also a safety net that if they hit a financial hurdle, the church will give back their money.
Guess I haven't seen or heard the negative pushback to it.