The Vinaya is also a view. Saying that meat eating is okay is also a view. Ultimately, they are rules, some of which are clearly outdated. Ancient India is not the Modern West. Look how Buddhism has been reinterpreted in China. They grow their own food. The West can clearly do the same. The Buddha said it is okay to change minor rules at his parinibbana.
I don't think the Vinaya is outdated at all. The rules are for bhikkhus who don't choose their food or possess money to buy food. Besides, there is no rules saying a bhikkhu has to eat meat or not eat meat. If a certain bhikkhu wants to become a vegetarian he can. It looks like some of the bhikkhus ( Mahayana) choose to be vegetarian. Is this against the Vinaya ? No, because there is no rule in the Vinaya preventing a bhikkhu from being a vegetarian. Since there is no rule preventing a bhikkhu from being a vegetarian then what rule is outdated ? Are we talking about allowing monastics to accept whatever being offered without like or dislike as being outdated or wrong ? If they know that the animals are killed for them then they can't accept it. If everyone offer them vegetarian food, that is just fine according to the Vinaya. They are neither directly or indirectly involved in the death of the animal. Their eating doesn't cause bad kamma . Also , what you put in your mouth doesn't effect the practice when it comes to enlightenment. The Buddha experimented with all these rules about eating and eating practices before but it leads to unnecessary pain , torture, and even death . His practice improved after he ignored these unnecessary / time wasting practices .
In the Buddha's teaching he placed more emphasis on what comes out of people's mouth rather than what goes in. That is why we see Right Speech as one of the Noble Eightfold Path. It is also part of the 5 precepts. If everyone become vegetarian fewer animals might die , but the problems of war, violence, crime, animal sacrifices, abuses, scandals, and the like will continue . But if everyone keep the five precepts, the issues we have in this world would greatly diminish. Also, sila ( 5 precepts, etc..) is an important aspect that can impact people's progress when it comes to the practice of enlightenment.
Some have more concern for animals, others are more concern about the poor, someone else might be concern about the environment. Are the ones that are concern about the animals more compassionate that the ones that are more concern about the poor and hungry ? Whatever area people are concern about depends on each person. Is it right for the ones that give money to the poor weekly look down on the ones who don't as being cold or undeveloped ? It just depends on which field people choose to focus their time and energy on. Each can motivate others to join in their chosen/favorite cause , but let's not put down others who don't share the same passion for your chosen cause.
The Buddha discouraged people of his time from animal sacrifices, discouraged the killing of animal in general, and discouraged the selling of meat or living beings. So people that discouraged others from killing and selling meat of other beings are not doing anything contrary to the dhamma. I see it as encouraging others to practice " Right Livelihood" and keeping the precept ( 1). However, these people shouldn't attack the people who eat meat because they are not the ones breaking the precept or getting involve in wrong livelihood. If you want them to join in and boycott the ones that are not practicing Right Livelihood and breaking the first precept then maybe you can try to convince people to join rather than attacking them for not participating .
There are some who think that monastics who accept meat are doing something wrong or are not as developed as they are, and criticized them . However, spirituality is not measured by what you eat because the ingredients you put in your mouth has little effect on spiritual progress.