There are likely some Protestants that either refuse to celebrate Easter or with Jehovah witnesses that celebrate on a different day to the Catholic Church.
But the vast majority of Protestant ecclesial communities can be caught celebrating Easter at the same time as the Catholic Church. Every single year since 1518.
Protestants have not used the same date for Easter as Catholics for every year since 1518. They did until 1582, but in 1583 the Pope introduced the Gregorian Calendar. From then on Protestants generally calculated Easter in the traditional way, using the Julian Calendar, still used in most Orthodox churches.
The original principle related Easter to the Full Moon after the Equinox and ruled the equinox was March 21. By the sixteenth century the rule was out of kilter with the principle. From 1583 to 1752 Easter was usually celebrated by Protestants, in the British Empire, later than Catholics. In some parts of Germany a different method was used from 1700 and it survived in Sweden into the 19th century. It was astronomically based.
Sir Isaac Newton tried to introduce an astronomically fairly accurate method in England, but eventually gave up saying the English would rather disagree with the sun and moon than agree with the pope. In 1752 the British Parliament decided to align the calendar generally with the Gregorian Calendar, though calling it the Georgian Calendar, and tables for Easter were produced on the Roman basis, though differently presented. This applied throughout the British Empire although it was binding only on the Church of England, Church of Scotland and Church of Ireland, as regards religious observance.
Very few Protestant traditions, if any, reject beliefs or practices simply because they are held or observed by another tradition. It might seem that way sometimes, but they almost always have some other reason (usually, that they find it to be contrary to Scripture).
Protestantism isn't a monolithic movement – within it, the founders of some traditions rejected relatively few Catholic teachings, due to their belief that Catholicism only fell away from the truth slowly (see, for example, Luther's perspective). Others rejected much more, and sought to re-establish the "primitive" or "apostolic" church based on biblical evidence alone.
So, for example, the reformers didn't get rid of the doctrine of the Trinity (also defined at Nicea). Most didn't get rid of infant baptism, though their understanding of it changed. They didn't get rid of Sunday worship, even though the biblical evidence for Sunday meetings is scant. And, similarly, they didn't find anything wrong with the Western church's dating for Easter, so they kept it.
As an aside, some Protestant traditions do take issue with the observance of Easter (regardless of its date), but for this position they have biblical and theological arguments much more sophisticated than "we don't want to be like the Catholics."
If you think about it, if being "anti-Catholic" were the defining characteristic, Protestants wouldn't believe in God, or the Bible, or salvation, simply "because Catholics do." Theoretically they wouldn't eat food or drink water or breathe air either, for fear of being like those Catholics! So hopefully it's now obvious that there's much more to Protestant vs. Catholic differences than that.
