Agreed with the OP.
Typology is an unbacked theory with little scientific credibility. There are reasons for that. It relies wholly on self-analysis, which is intrinsically flawed.
Naturally humans tend to inflate their abilities. Statistics have shown that the majority of people mark themselves as good drivers (around 70% believe themselves above average), highly capable socially (around 60% believe they're in the top 10%), and intelligent (need I explain this one? XD). Most people consider themselves 'important'. Yet obviously the majority of people can't be in the upper quartile (hence the phrase 'depressive realism'). This may reflect in personality tests, where with values that society has tried to encourage as 'good', people will inflate their opinion with it.
I see this a lot with the N/S divide, where the more common S is seen inadvertently by a lot (not necessarily all) as inferior - as bland, boring, prosaic, etc. Many people will deliberately delude themselves as such - I have an SJ friend who was convinced she was a 'P', since she saw Ps as being more fun and carefree (and if J's can have fun and be carefree just as Ps do, then we assume personality is ultimately something very flexible and it cannot be pigeonholed into sixteen types). Introspection itself is more likely to, according to psychology,
Another consideration is misinterpretations of the types themselves. Adjectives can easily be misinterpreted, lacking a precise definition. How would one define 'nice'? Is it through being pro-active and contributing to people's welfare, or is it through mannerisms, through smiling and being polite when one sees them, or is it through respecting people philosophically as of worth as opposed to practically? Is attempting to see people often and arrange meetings friendly and welcoming, or is it pushy? Is someone who isn't argumentative nice, or are they avoiding the reality of 'the world can't get on?'. Nice is a broadbrush example, but you can see how many can take words such as 'imaginative' or 'practical' and take them in different directions.There are various different kinds of imaginative and practical and it's crude to attempt to connect them.
Example: My father is an ISTJ, probably, and so is a friend. Yet as people, they are different - sure, they are both grounded in realism and precision, yet their attitudes to religion (apathy vs. strong belief), to competition and achievement (understand people vs. let them fail), their intelligence levels (high vs. medium) and their pretentiousness/confidence levels (low vs. high) - differ extraordinarily. Their backgrounds and experiences define them as people, not typology.
People are unique enough that to split the world into sixteenths will result in pigeonholing and simplifying the complexity of some personalities. There is a lot of differentiation within types, which perhaps reflects incorrectly on the types themselves - that various different kinds of people, often so different, can be typed the same, is that really an effective system of sorting personality? Perhaps, then sixteen groups are not enough. Perhaps, thirty two, or perhaps sixty four? Perhaps, even seven billion? Yes, people can be similar and have overlapping characteristics, however overlapping isn't a synonym for identical.
Typology just reinforces stereotypes, without really telling us anything new.
