No. This is so their technicians can easily log into your servers and solve problems if you need them too. Lots of their customers are newbies so they sell technical help as a service.

It is documented here: http://help.ovh.co.uk/InstallOvhKey and http://help.ovh.co.uk/Intervention as well as the way to disable this "backdoor". Note that there is more information available if you switch to the French language...