I don't think anyone should bring up DST when talking about time representations. DST is a stupid hack for artificially controlling economic forces, and has no meritorious bearing on timekeeping itself.

Let's face it: decimal time was really only intended for people doing lots of math work involving time. If the argument for base 10 is that calculations and representations are "easier" than base 12 (mainly because all modern human civilizations use base 10), why not make the argument that base 2 should be used, since computers virtually think for us at this point?

The real reason our representation of time is still so fucked up is that it has to be used by all humans, and all humans don't want to deal with lots of digits, fractions, floating point, etc. Sexadecimal is just simpler, even if we do have to occasionally jump through some hoops to keep this piece of crap timekeeping system in order. One second every couple years? Converting to decimal just to deal with little problems like that seems like a completely unreasonable suggestion to most people.