Hot take: time measurements are as convoluted as distances are in American units but everyone still uses those.
Yeah, it's retarded to harp on about how inherently illogical Imperial is when we all use similar logic for time.
That having been said, there are good reasoms why decimalisation of time never caught on. First off, the overarching reason for introducing the metric system wasn't just to create a more logical way of measuring things, but a
standardized way. Back in those days, pretty much every town in Europe had its own, wildly different idea of how long an inch was. Rather than getting everyone to adhere to redefined forms of age-old terms, it was a lot easier to just invent completely new ones, without all the bagage of tradition. In contrast, by the 1790s everyone in the Western world had long agreed on what a minute, hour and day was, and the Gregorian Calendar had become the standard for most.
And the reason why people had agreed on that already is that time is just fundamentally different from measurements like distance and weight. With the latter, all you really have to do is just come up with some measurements, and then use them as benchmarks. It doesn't matter if you're using feet or metres, you can accurately calculate distance with them because of the understandable value they represent. But you can't really do that with time on a grand scale, because concepts like 'days' and 'years' are so important, as they refer to and are influenced by natural phenonena that rarely correspond neatly to human forms of calculation. You can invent a nice decimal system of hours, days and months, but if it don't roughly correspond to actual 'sun-up/sun-down' days, or doesn't help you have a sense of when winter arrives, it's pretty pointless.
To this day we still have to basically cheat with our calendars and 12-hour days, in order to make them line up with a physical reality that doesn't give a shit about how we try to make sense of it.