I thought devaient être meant should have been...shouldn't it be les gens doivent avez été?

Hi Ann,

It is the old perennial problem of whether to use the imperfect or the perfect tense.

With the additional difficulty of ‘devoir’

Devaient être = imparfait 

Or 

Ont dû être  = passé  composé

Here the imperfect is better.

Devraient ( with an -r) être is should be. 

Hope this helps!

The imparfait here describes how things used to be, were at that time in the past ...