It's not the same thing. 'SELECT MAX(temperature) > 10 FROM ...' gets you all the datapoints, with a value of true or false. Moving it to the WHERE clause only gets you the datapoints where temperature is > 10. Yes, you can fill with 0 after the GROUP BY, but if all datapoints are less than 10, you get nothing back from the database. That's confusing: were all datapoints less than 10, or was there nothing registered in the time window I'm querying? Impossible to tell the difference. Not to mention some user interfaces just bailing: no data. I need to show a chart with a timeline of this condition being true or false.

Plus my actual use case is even more complex, not only do I need something like MAX(temperature) > 10, I need (MAX(temperature)) > 10 && (MAX(temperature) - MAX(dewpoint)) > 4.5).