The proper comparison to Amazon's offering would be Redshift. The reason you would go with Redshift over BigQuery is if your data is already in RDS, then migrating to Redshift is fairly straight forward (just whitelist the IPs in your security groups).

As others have stated, this offering directly competes with Google's Data Studio which was recently just announced.

It's not a product for storing data and then accessing it via SQL. It's a data analysis tool similar to Tableau.