I see that there is a lot of requests to implement external links to open in a new tab and I've seen an answer from one of the Jira's representatives that it won't be done. 

I still believe this request is reasonable for many Jira's clients (for example, youtrack I used before has this feature enabled), so what if Jira allows to enable/disable this feature? Opening external links can be 'disabled' by default as this is your decision, but I think the ability to enable this feature would help a lot of people and will be a competitive advantage of Jira.