First of all: Except probably the Elder wand there is no better or worse wand in the Potter universe.
Wands are just used to channel the magic of the wizard.
BUT: Every wand has its own specific properties and they match the character / abilities of the wizard it chooses.
So for each and every single wizard there is one wand that matches best. This wand chooses him and from that time on it works best for this specific wizard.
As stated in this answer after getting his wand the wizard learns from it and the wand learns from him.
"Oh yes, if you are any wizard at all you will be able to channel your magic through almost any instrument. The best results, however, must come where there is strongest affinity between wizard and wand. The connections are complex. An initial attraction, and then a mutual quest for experience, the wand learning from the wizard, the wizard from the wand."
Deathly Hallows - Pages 493 - 494 - US Hardcover
That said it is a bit like losing a good friend when your wand is taken away or broken.
In addition a wizard basically is not much more than a muggle without his wand: Not much magic is possible without a wand (unless you are a very experienced wizard, only some are able to perform wandless magic).
It is not that there are shops for wands at every corner (no Wand-To-Go in every town).
And there is only one known wand maker for whole Britain (Ollivander) in the books and without a wand it is even hard to get to his shop to get a new wand.
This fact alone should be enough to answer your question.
But as I reread your question I see, that what you really want to know is the opposite of the title of your question: Your last paragraph seems to suggest that wizards don't care enough for their wands taking into consideration how important they are to them.
For this question I just can say, that wands are strong magical artefacts and don't seem to break that easily. The only instances were we see an accidental destruction of a wand is the one of Ron and the one of Harry, and there are only two mentions of a wand broken deliberately (Hagrid's when he is expelled from Hogwarts and Lucius Malfoy's when Harry's wand destroys it).
So it seems that this simply doesn't happen often as wands might protect themselves from breakage in some way and that therefore wizards don't think about wand destruction.