And what's the problem with it? Fasting is not a Holy Sacrament. Communion is. You cannot command someone to do something voluntarily and out of love. Command and voluntary just don't jive. By denying them something that Christ commanded us to do "in remembrance of Him" is fasting by coercion, plain and simple. The Church has a monopoly on Communion. I don't argue this point as God instituted this monopoly, but it still makes it the only place where you can receive the Body and Blood of Christ, short of an Angel or Saint actually coming down and administering it. When access to this Sacrament is denied for some bizarre dietary law it is now getting in the way of salvation.
It's funny, but all the people I know in real life who have such issues with fasting do not spend time talking to their friends and clergy about how coercive the Church is by insisting on such things. They just do what they want at home, come to church, present themselves for Communion, and that's it. There are no fasting police (or sex police, menstruation police, nocturnal pollution police, etc.) at any church I've ever been to. No Church I am familiar with contracts spies or "schema-ninjas" to monitor the non-Sunday lives of its members. I don't know of any priest who interrogates communicants on these and other questions at the chalice. So what's the problem? Love God, be humble and repentant, and follow your conscience--no one at the church is going to know what you do at home.
But if something about the discipline the Church lays out for communicants (clergy and laity) in terms of fasting pricks the conscience of an individual who can't follow it, doesn't want to follow it, can't do it fully, doesn't understand it, doesn't agree with it, etc., then that person ought to talk to their priest/confessor about it, and take it from there. The Church has had this discipline for centuries, holding it up as a model for our own preparation, and dispensing those who need dispensations from some or all of its rigours. If it's worked for centuries, why should anyone think their problems with it will all of a sudden inspire a sweeping change? I think there's value in having a default, model practice to aspire to, and allowing people to build up to it when and as they can. It means there's always something "more" to shoot for, keeps us humble when we're not there yet, prevents us (ideally) from judging others who do differently, and encourages our fasting and other penitential disciplines to be done "within the Church" by having an accountability with one's priest/confessor.
That fasting is not a sacrament and Communion is is a valid point. But that doesn't mean that sacraments don't have certain prerequisites. If fasting is a coercive, overbearing imposition on communicants, why is Baptism not considered such? In order to receive Communion, you have to have been baptised. In order to be baptised, you have to believe the Orthodox faith (which means you have to learn it), repent of your sins, firmly reject Satan and all his works, be exclusive in your worship of and acceptance of Christ above all other gods, idols, and so on, and pledge to continue doing so throughout your new life. If you're doing that correctly, that's already a great inconvenience to the lives of Christians. Why not chuck that out too? The Church can't dispense from even one of those things, but it can dispense from some or all fasting. Is fasting really such a grave burden?
And yes, I just called fasting a bizarre dietary law. When I can have lobster but not a Big Mac I think the spirit of the rule is lost. If the letter of the law and the spirit of the law do not match it might be time to look at things. And there is nothing wrong with this. Fasting as it is done would force you to have a simple diet by medieval standards, allowing those with money to save on food and give to charity. Industrialization has changed the way we eat and many of the things that were simple back then are expensive, just plain unhealthy, or force us into medieval LARPing. Seriously, when was the last time you willingly ate potato and barley porridge for forty days?
This is a different matter entirely. It's important to recognise that the fasting traditions have changed over time, and even as we have them today, different traditions co-exist.
For instance, according to the canons of our tradition (Syriac), the default fast is a vegan diet, with no food or drink taken before dusk, and no alcohol at all. But even in those canons, you'll see dispensations issued generally that you don't have to ask your priest about. So you can break your fast at the ninth hour, or even at the sixth hour, if you can't wait till dusk. Outside of Great Lent, there's an allowance for fish. Beyond that, people can ask their priests for dispensations or they end up dispensing themselves according to their conscience.
I think we can legitimately talk about the current rules and discuss whether they need to be adjusted. Lobster may have been a "simple" solution in Greece, for example, but here it definitely is decadent compared to a Big Mac. Personally, I think the Byzantine rules are too complex and should be simplified, even if that means the "simpler" rule is more rigorous. It shouldn't be something where you have to buy a church calendar for the year to help you figure out what to do on what day. But again, that discussion can be useful in terms of how to go about revising the rules. It doesn't mean that we don't have to follow or be dispensed from the current rules, or that we should ditch fasting entirely. Our Lord never told us how to fast, but he most certainly told us we would have to fast. Edited to fix tags.