It's kind of a strange question. If nationality ties weren't a thing I would think about cricket very differently. I probably wouldn't support literally anyone against Australia, but as things stand, here we are. I feel like I can't be alone in thinking that it's the centre of getting into cricket in the first place. If I didn't have 'my team' I don't think I'd have a horse in the race at all.
It's nice to think I am a noble 'I want cricket to be the real winner' just because I occasionally put on a neutral series when there's nothing else I feel like watching, and it's particularly tempting to think I might be a superior type of fan to those weird youtube commentators who only watch and know anything about their own team. But I don't really believe any of us are actually that pompous.
That's a very interesting point. I think this perspective will change between cultures/regions. If I'm from a region/country which has always had a team competing at the highest level in a number of 'world' sports, I think I will always have 'my team' and I will never have a situation of having to go for someone else.
But if I'm from a country/region/culture that does not compete at that level, or only just started to, then I think it's a totally different situation.
Case in point, if you talk to any of the Bangladeshi cricket fans who watched cricket in the 80s or 90s, you will find them supporting either India, Pakistan or West Indies.
Similarly, Sri Lankan fans in the 70s used to support India and Pakistan.
A great example is the first ICC Champions Trophy in 1998 in Bangladesh where Bangladesh themselves did not play. The games were very well attended and the popular teams were India and Pakistan with most support.
Another example I remember is the Pakistan vs Sri Lanka test match in Dhaka in 1999 before Bangladesh's test status which also had support for both teams.
This is because a generation of cricket fans in Bangladesh grew up without having their 'own national' team but the sport was still popular and they supported usually their neighbours.
This is also very interesting because Bangladeshi fans are now known as some of the more unsporting ones who go quiet when the opposition hits a boundary. But even if you look at the recent India vs Pakistan match at Asia Cup, both teams would have felt they were playing at home because there was equal support.
This also the case with Football which is popular all over the world irrespective of whether the respective teams qualify for the World Cup or not. So you will have teams like Brazil, Argentina having fanatic support in the subcontinent during the World Cup because you just get used to the fact that you're team does not compete at this level, so by default you have to find another team that you connect with and root for them.
Then there's the Football leagues which are extremely popular all over the world. Manchester United is more popular in the subcontinent that in England.
Recently when I was watching the El Classico, someone asked me why I was so excited about it when neither of the clubs are 'my clubs' whatever that means.
I think if you love a sport and your national team does not play it at the highest level, then it's a different situation and you will have an 'adopted' team.