Whatever your opinion on the direction Marvel should take the Spider-Man comics, we should be able to agree that there will be reasons for differing courses of action. There are reasons to bring back the Spider-Man marriage, and there are reasons not to do so.
There is another discussion about reasons to bring back the Spider-marriage. Let's focus on the advantages of Peter Parker single, even if you don't believe these particular gains are worthwhile.
The main argument is that there are more stories that Marvel can tell with a single Peter Parker than one who is married to Mary Jane. The majority of stories you can do with a married Peter Parker and Mary Jane can also be done with an unmarried Peter Parker and Mary Jane in a stable relationship. The exception is the stories that explicitly require the two to be married, which are quite rare. But with a single Spider-Man, writers have access to other material including but by no means limited to the stories you can only do when Peter Parker is in a stable relationship with someone else (e.g. Black Cat, Sabra, Norah Winters, an entirely new character, etc.), the stories Marvel can only do when Peter Parker is in a unstable relationship with someone else (e.g. Black Cat, Sabra, Norah Winters, an entirely new character, etc.), the stories Marvel can only do when Peter Parker doesn’t have the love of a beautiful, supportive and good woman, the stories Marvel can only do when Mary Jane is in a stable relationship with someone else, etc.
Marriage removed tension from the series, because readers knew that the relationship will survive conflicts. It also produced stability, as it was difficult to repeatedly convince readers that Peter may not have a loving supportive wife to go home to. Even if a particular story ended with Peter and MJ apart, as long as they were married, it was pretty that they would eventually get back together.