Safety Concerns:
Your post is EXACTLY why BA passengers are looking forward to Mixed Fleet, why Mixed Fleet is necessary and why it is also necessary that Mixed Fleet be kept separate from the influence of the hard-line BASSA members.
An example. My hubby reserved a local establishment for the England/U.S. World Cup game. He didn't host the bar but he did host the food and several large screen televisions were brought in for the event. There were even tables and televisions outside under canopies.
It was a simply wonderful event. Heavily attended, wonderful exchange between the Company and community, a definite plus. One of his employees came up to me and said "We've never had anything like this, it's simply brilliant.".
If my husband used your and BASSA's logic the event would never have happened because his first thought would be "If I do this, then what will they expect next...I'm starting down a dangerous path.".
Thank goodness he, and the three unions that participate in success with him, have a different approach.