Who knows how long they will support that, I've seen ploys like these before where in a couple years they'll reduce that free tier to nothing and jack up the price of the entry level.
Edit: Equivalently any SAAS sucks since they may in the future raise their prices is your argument.
This is a very real argument though? Reliance of a core part of your saas on another company, who is liable to change prices at any time, is a real business risk. The Google Maps API pricing change is a big example.