The quotes you personally selected actually admit that the technical aspects of the accusation are correct, but claim that the ability to exploit the gear to spy on their users was not intentional but instead a side-effect of the company's incompetence.
Is it "technically correct" to call standard diagnostic software that most telecommunications manufacturers install on their gear (and which does not allow unauthorized access) a "backdoor"?
Vodafone, the company that Bloomberg claims was targeted by these backdoors, publicly contradicted Bloomberg. They pointed out that the diagnostic software did not allow unauthorized access:
> The 'backdoor' that Bloomberg refers to is Telnet, which is a protocol that is commonly used by many vendors in the industry for performing diagnostic functions. It would not have been accessible from the internet.
> Bloomberg is incorrect in saying that this 'could have given Huawei unauthorised access to the carrier's fixed-line network in Italy'.[1]