Would you like going out with someone who constantly talks about issues she's having in her life?Dating isn't a therapy session—it's an opportunity to spend time with someone else and enjoy their company.
Unless you're dating someone you knew previously, and they are already familiar with your late spouse, he or she is naturally going to be curious about your previous marriage.
It's not wrong to date because you're lonely or want company. However, if you're dating because you think it's going to somehow fill the void or heal the pain that comes from losing a spouse, it's not going to happen.
Dating does give you the opportunity to open your heart to another person and the chance to experience the unique and exquisite joy that comes with falling in love again.
If you have family and friends who are doing this, they need to be told privately, but in a loving manner, that this behavior is not acceptable.
If you wouldn't let family or friends treat your spouse that way, why would you tolerate that behavior toward someone else—especially when your date could become your future spouse? If you can't do that, then you have no business dating again.