It isn't mindset. There is a reason birds fly south for the winter.
I've lived in 7 different countries all with different climates and I've seen in every place there are some who hate the heat and some who hate the rain, some who love the heat and some who love the rain. This is the only country I know where I've heard anyone say they want to get away because of the weather. And for the record, on rainy days in hot countries, NO-ONE goes out. They have sense to not put themselves through that displeasure.
All this toxic positivity nonsense is getting out of hand. You can't force people to love the same things as you. It's like trying to force someone who has a taste aversion to strong salt and vinegar to tell them it is all in their mind and to try it on different foods, when the muscles in their face are literally reeling from the intensity of it.
I bet half the people saying how 'wonderful' the rain is, if offered a villa on a Caribbean island with their whole family, would be like 'let's get out of here', in an instant.
How many times have you heard a nature documentary talk about the rough winds of winter?
Yes, maybe you can make the most of it and try to get through it, but that doesn't mean you can't express how difficult it is. Winters ARE hard and there is a reason everyone breathes a sigh of relief when summer comes around.
And if being outdoors in the winter and rain is so normal, then why do we live indoors? We build houses because we physically cannot handle the cold. Yes maybe in small doses, but an hour or two of puddle jumping doesn't equate to filling the whole day like you can in the summer.
The cold can make you ill too- the immune system is affected by exposure to cold and dry air and viruses spread better in lower temperatures.