What makes DVC a better choice than other on site choice, or other choices off Disney property? I can easily offer my rationale as to why DVC was and is better for us but I can't do it for anyone else.
However, with that said some things to consider would include (but not be limited to).
1. Do you like WDW enough to go every other year, every year, or more often than once a year? Then maybe DVC is for you.
2. Does your spouse/significant other like WDW well enough to go every other year, every year, or more often than once a year? Then maybe DVC is for you.
2. Does your "family" prefer to stay on-site? Then maybe DVC is for you.
3. Do you tend to stay at moderate or better resorts? Then maybe DVC is for you.
4. Can you really afford DVC, including the maintenance fees? Then maybe DVC is for you.
5. Have you done enough research that you can say you have a reasonable understanding of how DVC works, what's the best use of points, etc? Then DVC may be for you.
Other things to consider would include how many people there are in your family, what size unit you would typically use, how flexible you are in terms of when you can take your vacations, your eating habits when you are at WDW (and I'm sure there are a host of things I have left out).
If you love WDW, if you tend to go at least once every other year, it you prefer to stay on site at moderate or better resorts then DVC is something to consider. But, make sure you think it through, ask lots of questions, run the numbers and then think about it some more. After all of that, maybe you will decide that DVC makes sense (or not) for your family.