Mental health being impacted is a pretty neutral phrase. Within a lot of coping strategy work, it's a common practice to track what 'impacts' our mental health so we can be aware and handle our own health, even when we aren't sure how to articulate it. Impact doesn't mean negative, it just means we noticed an effect and it's acknowledged not all of them are under our control - I often have dreams that affect my moods and mental wellbeing, for better and for worse & I've little control of my dreams, but being aware of their impact means I know after a bad night - like one I had recently where I was reliving my mother trying to kill me in new ways and locations - I know what I can do to try to minimize that impact because I had a lot of coping skill training as a child. Doesn't make it easy and sometimes the impact is all I can articulate, I can't always put an emotional label on these things that I feel is accurate. If I say something has impacted my mental health or similarly vague, that means something has had an effect and I'm not sure how to otherwise explain that & may need help finding better words, not that I'm trying to get something.
While I agree the UK and other places may have pathologized too much as part of a spiral where things aren't taken seriously so we apply a fancy label which is then still not taken seriously so we up the ante further and lost some of the nuance along the way, this desire to erase suffering in the UK is ridiculous. Palestinian doctors - and many others who live in on-going conflict zones - have discussed the different language used around mental ill health, but even with different language, it's still noticed as it has been across place and time.
Life can cause mental health problems, trauma, etc, but very few people actually fall into this category ( in the UK).
Using US stats, because that's where has the most data, and I don't imagine are too different from the UK, 61% of adults have at least one Adverse Childhood Experience, and 16% have 4 or more. I'm in the latter category, with the most unwanted perfect score ever. There may not be war on our own soil, that does not mean we are at peace or that conflict isn't going on in our home and the environment around us. Things are more complicated than that.
Most mental health problems are not in any way related to life experiences and whether we talk about our feelings or not.
More and more, these conditions viewed as 'mental' are shown to have physical, genetic, and environmental components. Bodies, including our mental state, are complicated - pretty much how all illnesses are expressed has some environmental component.
I personally prefer therapy around developing coping strategies over talking, but we don't fix anything by not talking about it. The people who taught me not to talk about it or to only use minimal language were not the one who cared about my well-being.
People are not taking care of mental health though, that is my point. They are just flashing the "mental health" card, to get what they want, without actually having any understanding or knowledge of what mental health actually means.
Maybe in some cases, there are those who intentionally are assholes in any group and those not intentionally doing so may benefit coping skill training that includes emotional skills and in other cases they may mean more than "I am annoyed" or "I don't like it when" or what they're feeling doesn't fit what they imagine 'annoyed' or 'don't like' should feel like.
Not everyone actually has the skills to label emotions well -- actually, humans in general are pretty bad at this, even more young ones, and we're generally terrible at identifying why we're having certain emotions and the sensations we link to them. They may just know something has been impacted and that's the language they have, it's likely worked for them before, so that's what they use. Your posts OP make it sound like this should be a very easy skill that people are just purposefully choosing not to do to manipulate others, when really it's like identifying any sensory information - we rely on experience and the skills we've developed and as a society, we talk a lot about mental health now - which is why people use that language - but these skills are no more prioritized than identifying bird calls. I think as a society we have a lot of surface representation of feelings and other aspects of mental health and assume people will get it from there and I don't think that's happening.
I think it's pretty sad that you're seeing many people with obvious skill gaps and you write about them in such a negative dismissive way. You can claim you give people the benefit of the doubt all you want, but that is not what is coming across here. I'm really glad young-me got better help from people who saw my gaps, understood my behaviour was my poor attempt at communication, taught me & tried to limit the damage of those who looked down on my limited language and emotional skills.
For all your training, I'm not sure you understand what mental health actually means, at least, not holistically as something that can be impacted by our daily lives just as much as the rest of us. You seem to have a rather pathological view of it that it's only to be discussed as part of an illness, that regular emotions aren't part of it. Having had mental health care from early childhood with no one using that term until I was 15 & getting assessed for possible hospital admission (I did not qualify, but the admissions assessment team was amazing, confusing for teen-me, but long-term helpful), that's not how a lot of therapeutic systems work. Most of them I've experienced are about daily life emotions and coping because, you know, even with a trauma disorder, I still live one day at a time like everyone else & the dealing with the little things prevents snowballing into worse.