This is a funny question, when you think about it.
Are dolphins and mushrooms and prairie dogs extremists? They have no money, no possessions, after all.
Funny thing is, it was Gautama Buddha who coined the term, "The Middle Way between extremes." Funny thing is, it was Gautama Buddha who lived his life, as Jesus and Lao Tzu did, without a house, taking only what he needed for basic daily subsistence, and he implored his followers to do the same.
Every religion teaches Moderation, the way between extremes. The Buddha's epiphany was that you should neither deprive yourself nor indulge yourself. He had been living in a culture of ascetics who deprived themselves, and they condemned him for deciding to treat himself to healthy food and living. Jesus, on the other hand, had been living in a culture of greed, and they condemned him for deciding to treat himself to forsaking addictive indulgences.
Sparrows and slugs and centipedes, living without possessions, using no money, live the Middle Way! They take no more than they need and they take no less than they need. "Give me neither poverty nor wealth," the Bible's Proverbs say. This is my aspiration. Modern humans, on the other hand, live in extremes. They live under the principle of possession, which creates extremes not found in wild nature--extremes of wealth and poverty, extremes of obesity and malnutrition, extremes of war and peace, extremes of mental moods, extremes of addictions and asceticism, extremes of hatred and affection.
Not according to my opinion, not according to religious dogma, but according to the very law of nature, if you but look around you, is this: to live with money and possessions is to live in extremes. If you think that our inventions of money and possessions have not created extremist stress on our own minds and bodies and environment, think again.
I am not an ascetic.
Please see the essay, A Culture Living Abundantly Without Money Today, to see an example of a whole culture living completely between the extremes.
If you are the only dry person in a room full of alcoholics-in-denial, they will surely consider you an extremist. They will also call you self-righteous, even if you say nothing.
See also 18. Isn't it hard living your life of asceticism?