With Inno's fixation on Event building rewards that have massive populations, there really is no longer any reason to build either a Habitat or an Innovation Tower if the primary reason you're building it is for population. If anything, the population from either of those buildings is now more of a liability than it is an asset because it forces you to increase your Happiness in some manner to offset the population. In one of my worlds, I have well in excess of 20,000 unemployed folks (have I mentioned lately that I hate to spend Diamonds on...well...anything?), and I have several fully upgradeable Event rewards sitting in my storage because I don't need even more unemployed citizens.
I've deleted two Innos so far. One was around level 6 and the other was 4 or so, so in neither instance had I invested an amount of FP that gave me any reason to delete them. Had the been level 10, I would have had a much harder decision to make. That point where the decision changed from "easy" to "difficult" is going to be different for most players.