Employers are interested in UCAS points because they give a very good indication of the standard of the university (and hence the course) that you are at. University courses are pitched at the students sitting them, and if the lecture halls are filled with people who failed to get higher than a D in physics (for example) then the physics lectures will be pitched accordingly.
In addition, A-Levels are the last point at which candidates can be compared across the board.
A point on masters programs: they are often used as money making machines for big universities. The universities are fully aware that there are lots of people who would like to top up a mediocre degree with a fancy sounding masters.There are also a lot of foreign people (especially Asian) who would like a degree/masters with a British university stamp on it. The standards are often (but certainly not always) lower that would be expected for the undergraduate courses, where the selection program is far more rigorous. Employers are generally aware of this.
In addition, A-Levels are the last point at which candidates can be compared across the board.
A point on masters programs: they are often used as money making machines for big universities. The universities are fully aware that there are lots of people who would like to top up a mediocre degree with a fancy sounding masters.There are also a lot of foreign people (especially Asian) who would like a degree/masters with a British university stamp on it. The standards are often (but certainly not always) lower that would be expected for the undergraduate courses, where the selection program is far more rigorous. Employers are generally aware of this.