They, like Tyndale, got caught up in politics. Wycliffe and his associates were acting in a time of great turmoil. The Black Death had wiped out some many peasants that their labor was at a premium. That set them against nobles and the Church—which was a major landowner in England. If Luther had no come down on the side of the princes during the Peasant Rebellion in Germany, he would have been finished.
Even Wycliffe, a young man at the time of the plague, did his most important work in the decades after.
The labour shortage resulting from the plague did, of course, do much to bid up wages and improve the lot of peasants over the next three centuries or so. But the tradition of religious freedom would require another 500 years or so to take firm root in the Old World, with America getting ahead of the curve by a century or so.
It was thus inevitable that these early reformers got caught up in politics, either as an initial means of self-defense in cases like Wycliffe and Luther or as an eventual means to trade places with their former oppressors as in cases like Cromwell and Calvin.
The publication of the King James Bible overshadowed any of these men as a means to bring about the concept of religious freedom and establish it as a cornerstone concept in our new nation.