The option to hardfork to a larger blocksize was freely available, but not enough people chose to go with it. The majority decided that a softfork to an opt-in 4MB blockweight with SegWit and Lightning was a more sensible option.
Did people really choose not to go with a hardfork? I don't think it was ever up for debate. The core team refused to go along with a 2x increase, so instead it was picked up by a different team which basically made it a hostile takeover of Bitcoin. There was never a search for a consensus around the blocksize increase, because core team refused it in the first place. There is nothing dangerous about a hard fork if you get a consensus, but since the devs said no that was the end of it. The majority of people in the spring opted for segwit plus 2x, but then core said no to 2x so the 2x idea became basically a competing chain and that risked the network so it lost support.
Chances are, not everyone sees it the way I do, but this is my take on it:
I despise the current usage of that phrase "hostile takeover". It's abhorrent and I'll explain why. (//EDIT: in a much longer post than I had planned, it seems)
It's likely that because Core have done such a successful job of maintaining Bitcoin, the majority of users are willing to go along with whatever Core think is best. However, that doesn't mean a hardfork is impossible without Core's blessing, just that it's highly improbable. I'm still not at all comfortable with people describing fork proposals as "hostile takeovers", as I believe it sets a dangerous precedent and strongly implies that one development team is in total control and/or ownership of Bitcoin. It's not like we're forced to do what any particular dev team think is best. The dev team don't own the chain. We choose to run their code if we like what they're doing.
Consider that using an emergency exit in a fire, for example, wouldn't be called a "hostile departure". That's the way in which we should think of proposed hardforks. Not as someone trying to "seize control", but as a way of users having an escape route from anyone who did somehow manage to seize control and act against the wishes of the users.
Because otherwise (and this is the crux of the argument), the moment you suggest that someone is trying to take over, you're consequently also suggesting that Bitcoin has a centralised authority, that this authority is in control of Bitcoin and some rival authority is trying to wrest that control from them. I don't know about you, but that doesn't sound like any Bitcoin I've ever been a part of. So that argument makes no sense to me. It's an affront to freedom to say that no one can code another client and allow the users to decide for themselves. You literally can't have a hostile takeover if it is the users who have simply opted to run a different client with different consensus rules. Creating clients with different consensus rules isn't a takeover, hostile or otherwise. Because they only have influence if the users support them.
If enough users disagree with the direction being proposed, they should always have the option to bail out of it and go their own way. Perhaps there's only an infinitesimally small chance that Core would ever make a decision that the majority of users didn't agree with, but if the chance is there, however miniscule, we shouldn't preclude the possibility of a hardfork without that dev team on board.
So coming back to 2x and my previous post, if a vast majority of users had wanted it, even if Core didn't, the users would have had the freedom to leave. It wouldn't be a hostile takeover because it's the users making that decision to change. It just so happens, the users didn't decide to make that change.
Conversely, after a split has occurred, the lesser of the two chains is undisputedly the altcoin. If the altcoin then tries to claim the mantle of Bitcoin, despite having insufficient support, you can call that an attempted hostile takeover to your heart's content. You won't hear any complaints from me there. Because that's a smaller group of users deliberately trying to take something from a larger group of users against their wishes.
