Why do your customers even need to have expertise in the DBA you're using? We just sell them a black box (usually VM images), with a few endpoints to extract data in standard formats. They can use whatever they want to connect to those.
Maybe one customer wishes to run their databases in a cluster distributed across two continents.
Maybe another customer has bought Oracle and the installation still has room. Also, they have a custom backup scheme that takes their load patterns into account.
Customers wish many things, that doesn't mean they're relevant selling points. It just sounds bad judgment to me to tie yourself that way, unable to take advantage of the RDBMS to the full. And have you even tested running your (hypothetical) application in a distributed Oracle cluster across two continents? If not, how will you support it?
