From what I remember and what my research revealed, Infect’s matchup against Twin was unfavored to even depending on what Infect ran maindeck. Numerous pros, including Todd Anderson following his SCG win with Infect, said that Infect was only the pick when Twin was at an ebb. It came down to Twin having more cantrips and thus being more likely to find its pieces than Infect. Also the counters and Blood Moon could be brutal.
Players like you with maindeck Spellskite and Wild Defiance certainly had an easier time. However, most apparently did not and Twin was adapting to Infect in the later stages of 2015 with Roast, Electrolyze, and Dispel moving to maindecks.

I had literally only played Infect from the days of Scars of Mirrodin until 3 weeks after the printing of Fatal Push. That was my only deck. And I LOVED the Twin match as much as the Tron match.

Spellskites (2 I believe), 4x Vines of Vastwood, 2x Dismember all in the main deck and 3x Wild Defiance out of the side plus Spell Pierce made for fun times for me! And from what I remember that was the standard deck list for everyone else at the time.

it’s always the same nonsense people say when they don’t want their deck to get banned and invent fictional reasons about why the world will fall apart if it does:

‘don’t ban DRS the meta will become a graveyard infested hellhole’

‘don’t ban birthing pod, aggro will run amok without the premier aggro ‘police”

‘don’t ban Twin least nothing but linear combo remains’

the trend continues now with UR phoenix (which i do not believe should be banned), for which it’s pilots laughably claim to ‘steal points from unfair decks and give them to fair-uninteractive ones’, yeah? and how exactly does phoenix win against combo? gut shot them? it’s not that fast either, if anything creature decks like spirits and humans are the best MUs for phoenix and not fast combo decks with whom it has trouble interacting

the concept of ‘police decks’ is ridiculous and needs to be abolished if we’re ever to move forward in terms of magic theory

Every banlist announcement you see that argument trotted out. I think most people believed it at the time of the ban. Having actually examined the data I’m pretty sure you’re right, it was simply the best deck and did what any best deck did. Now that there isn’t a presumptive best deck year after year, there’s a lot more room for creativity.

UR Twin policed players’ creativity and incentive to explore <10 years of cardpool more than anything, which threatens to be a problem whenever there’s one deck that rewards mastery too well.

That is possible, though very hard to say. It appears that Twin was simply sitting atop Modern rather actively pushing anything out. This suggests that the lower tiers would be relatively unaffected by the unban compared to the upper ones.

My expectation is if you’re running a low tier or completely rogue deck then it’s a passion project that you’d stick with regardless of the metagame. Upper tier players are more likely to be interested in winning and be willing to switch decks as a result. Thus if it’s the random noise that is drawing player hatred no banning or unbanning will fix it.