The interesting part is that you're wrong and right at the same time!

Adding decimals increases the value of the network as more humans can access it as a unit of account & medium of exchange - meanwhile increasing the accuracy of payments for everyone.

New Bitcoins will be distributed to miners that were never in existence though.

So the net effect will be deflationary - as we can't exceed the ~21M barrier by adding decimals & surely we'd be doing this for people clamoring for it as Satoshis become more valued for goods and services.