There are a few reasons for this, one of which can be attributed to human nature - we aren't designed to worry about the long term future, especially when we need to worry about more pressing matters like how to pay next month's rent. Another is the disinformation campaign conducted at considerable expense by the fossil fuel industry and its political pawns, who in the US now include the entire Republican Party and many of the Democrats. Finally, and not insignificantly, the blame goes to Jim Hansen and many other climate warriors who did so much to reveal the climate change problem but then called "Wolf" too early and often. Twenty years ago we were bombarded with with warnings of dramatic and rapid changes in global temperature, as well as associated changes like more and worse tropical storms.
These things mostly have not happened. Instead of a rapid increase of global temperature, we have seen a dramatic slowing in the rate of temperature increase. The US has seen a big decrease in the rate of tropical storm landfall. The gradual retreat of glaciers is invisible to everyone but the tiny minority of citizens who see them on a regular basis. Drought is severe in some places, but has been a familiar phenomenon forever. Add in the fact that one year of big snow makes a more dramatic impression than a barely statistically significant uptick in global temps and it's easy to see why few are paying attention.
Overall, climate models have proven to be rather poor in prognostic mode.
None of this, by the way, is evidence that climate change isn't happening or isn't very likely to become far more serious. It is a fact, though, that many put far too much faith in the prognostic capabilities of climate models squandered their credibility with rash predictions. It's not a new phenomenon that Cassandra is never believed until its too late. Homer was revealing fundamental truths about human nature way back when.
I have become convinced that chances for serious action to limit carbon burning are very poor until and unless pretty catastrophic consequences are seen. Of the big players in carbon consumption, the US is nearly unified against any action that would increase energy prices, China shows no signs of curbing its vast appetite, and India votes for magical thinking. Only Europe occasionally shows signs of climate seriousness - and it's probably too small a player to count.