ALL public charging is "emergency only" for me or a rare longer distance trip in our non-Tesla cars. Using fast chargers like these represents such a small percentage of my driving energy usage that the convenience, when needed, is well worth the price. I signed up for ChargePoint in 2013 with a $20 deposit, basically as insurance. My balance is now $15.36 without adding any funds.
This location will be useful because:
1. It's at a high traffic freeway intersection.
2. The number of stalls guarantees that a working one will be available.
3. The pricing structure guarantees that people won't be over-staying and charging to 100%
4. There are no manufacturer sponsored free charging plans that cover these chargers, so it will not be clogged with free-loaders.
It's also one freeway exit from the Mountain View Supercharger, so if you're in a hurry and there is a line at the Supercharger, you would be able to get enough energy here to continue on your trip before you even got a plug at the SpC. However, unlike the San Mateo Supercharger and its co-located Chargepoint fast chargers, there are no services (stores and restaurants) at this site.