Unless you're an astronomer, you probably don't care about condition 2. Many countries still shift wall time around by an hour twice a year for DST - if people are okay with that, solar time being offset by a few seconds is insignificant.
Even for astronomers, I suspect that preserving conditions 1 and 3 is probably more valuable than 2. It's easier to correct for the uneven rotation of our planet than for an uneven timescale.