IPO's are literally, what destroy's every great product.
If you are interested in making money (like Microsoft), and just sucking blood from those that have invested their infrastructure into you (like Microsoft) then an IPO is the way to go.
If you don't care at all about your customers, and are there only to ensure you can take more of their cash, then do an IPO.
All your energies that you have diverted into making a great open source product will be destroyed because you now have to channel everything into making profit, and it will hurt your product.
I do think it's a bad decision.
The next step after IPO is a large corporation (Microsoft) just buys you up, and adds you to their cloud as an OS option. An OS that will have to run on their backend, for $29.99 a month.