Why are the vernal equinox and autumnal equinox in the 24 solar terms not called vernal equinox to autumnal equinox?

I understand that the day and night time of the vernal equinox and the autumnal equinox are the same, both of which are 12 hours.

So it is called "minutes", and the solstice in summer and the solstice in winter are two extremes. One is the longest day and the other is the longest night in a year, so it is called "Solstice".

The above is my personal opinion.