I'm entirely confused, I'm new to the forums but have been playing since Beta 1.
Why is there even a discussion about a paid online mode? Is it not clear that the game is a pay once, get everything deal? If there was even the slightest hint of a subscription I would've forgotten entirely about this game.
Why is there this so called demand for a subscription? What is wrong with the game not being sub-based?
In general, why is this question constantly being asked?
It's the perceived weakness of P2P in regards to multiplayer. This poll was poorly worded and I think it affected the result (but not massively). The suggestion was to have a subscription based model alongside everything else so that game play types that would benefit from a client server model would be more available. The server model costs more to maintain so the subscription is required to maintain them whereas the P2P model is comparatively cheap to maintain so enables the pay once mode with smaller ongoing costs for content packs and vanity items.
Part of people's issue is a perception that someone asking for server based is only after PvP. While that is true for some, others are keen so that large co-op events could be more easily supported.
Even if 12% of the player base was willing to subscribe (based on the results at the time of writing) that would be a substantial ongoing revenue stream for FD.
I voted for it providing it didn't remove any other playing modes which is the same as what the OP suggested. I do wonder why people are so vehemently opposed to an idea that would not affect the current playing modes, adds choice, and is not a requirement for anyone.
Then again plenty of people hated the price of ship skins and that didn't affect their games nor was it a requirement to play.
Hope this answers your question.