Arguably yes, though in practice they tend to lack numerous qualities cranks have.
"you can't do experiments"
That's really the one issue, and speaking as an experimentalist it is a big one.
Proponents of string theory generally tend to be quite reasonable in discussion however (recognizing the experimental verification issues for example), and don't practice the many logical fallacies and whatnot that cranks seem to love. You don't hear them arguing about how "big [somebody]" is keeping them down for example.
And yeah, once someone reaches tenure they pretty much have full reign, including being able to be a crank. There isn't all that much people can do about it at that point. Being formerly sensible isn't fullproof protection against crank-ism, some people just... snap (or move on to other topics they were never scientific about in the first place).
"you can't do experiments"
That's really the one issue, and speaking as an experimentalist it is a big one.
Proponents of string theory generally tend to be quite reasonable in discussion however (recognizing the experimental verification issues for example), and don't practice the many logical fallacies and whatnot that cranks seem to love. You don't hear them arguing about how "big [somebody]" is keeping them down for example.
And yeah, once someone reaches tenure they pretty much have full reign, including being able to be a crank. There isn't all that much people can do about it at that point. Being formerly sensible isn't fullproof protection against crank-ism, some people just... snap (or move on to other topics they were never scientific about in the first place).