Provided that Meat Loaf is capable of performing and enduring the demands of putting on a performance, it is his choice whether or not he can perform. If, due to his age, he is unable to offer the fan the desired performance, it is the fan's responsibility to not attend his performances. If he is able to attract an audience to offset the cost of his investment, he should be allowed to do as he pleases.
I would say no, Meat Loaf is not too old to do live performances. Just like anyone else in any profession would choose for them which age they felt was best to retire, live performers should be able to make that decision for themselves as well. As long as he feels that he is still up for performing, I say go for it. Age is just a number, how you feel is what matters.
Meat Loaf has been a popular performer for many years. As long as he is still able to put on performances for audiences that enjoy watching him, he is not too old to do live performances. Also, there are countless performers that have never retired, ones that are older than Meat Loaf. In short, the only person that can decide if Meat Loaf is too old to perform live is Meat Loaf.
As long as you can stand up on that stage and rock out you are never to old to do live performances. As long as people are willing to pay and they still like what you do then you have every right to perform. We are a very ageist society and we need to get over that.