Well, what all did Paul say, in totality? In 1 Corinthians 7 Paul says he has no "commandment from God" about this. Paul says that he wishes that everyone was single like him ── not that God wishes it. He says that he, personally, is content with being single ── but he admits that not everyone is like that. He says that it's good to stay single, but that it's better to marry if you have strong desires. Paul "supposes" that it's better to stay single because of "the present distress," some crisis that the church in Corinth was dealing with at the time. He says you're not sinning by marrying. Paul says a widow would be happier if she stayed single, but he admits that this is just a personal opinion. Evidently, many people are not happier being single. In 1 Timothy 4:1-3 Paul also condemns people who forbid marriage. And if Paul wrote the Book of Hebrews, then he also said that marriage is a good thing.
If you want to argue that Paul wanted every Christian of every future era to stay single, well, there's lots of other things Paul said that you kind of have to, well, ignore.