Actually, MGTOW is a gradiated response. It has grown over time in (slow) response to several cultural shifts and many policy shifts in government which supported those cultural changes. Some of those cultural changes were positive, but profit motive and wealth transfer and extraction by industry plays a larger part in government supporting the destruction of families. Government policy has given incentives to women to do so, and to reap benefits. And so they do so to get their due reward, and they get to do so while retaining their claim to victim status too.
MGTOW is Awareness, Recognition, and Acknowledgement that there are other choices for living one's life . Why be a willing slave to a structure and system which supports servitude and misery for those who chose to enlist? Marriage is but the first step. The contract itself is not worth anything. It is the dossolution of the contract in which financial benefits will be reaped by those who pursue the dissolution of the marriage contract via (in general) wealth extraction from the male. The marriage contract is at best, an opt in for financial indentured servitude for a period of time, and can be much worse because it can make one a financial slave for life.
When one chooses his own path and rejects marriage and the paths that lead toward servitude in a system set against men to the benefit of women, others may refer to it as a lifestyle. It is a lifestyle choice at that point, and a dangerous one for women and the system which supports them.
For those who clal it a philosophy, well, they are somewhat off base but as long as you muddy the waters, have it it. Call it what you want. Others don't have to subscribe to how you label it. If by philosophy, you mean a way to live one;s life and thus back to a lifestyle choice, then perhaps so, it's just more labels.
More than awareness, or recognition, or Acknowledgement, MGTOW is a response. It's simply teh next logical step which has taken it's sweet time in the cultural repsonse to the shifts which occurred decades ago. The initial pains were minor, and they grew over time. Overreach occurred and for those who have lived through the period, they now see, either in hiindsight, or as a glaring undeniable truth with the need for hindsight, that the system as it stands as supported by government for relationships (marriage) is a sham. It's a system of slavery and more men than ever before are refusing to sign up or opt in to that system of control.
Men have been removed form their families, and then blamed for leaving them. That's no incentive to want to start a family. Women threw off their oppressive gender roles and we've heard nothing about those roles but how the patriarchy hurt women. But their system depends upon men adhering to those same male classic gender roles. Women removed their part of the agreement but expected men to keep theirs. For the most part, and for a very long time, men did. That is changing now. Those entrenched in the established system are threatened by men making different choices. That was always the problem. They knew men making the same choices, and be willing to make the same mistakes. They went too far in their effort to shame men over time that in so doing, they accidentally taught boys and men to actively think about and dislike what they were going through and why. They over used the victim stance for women. They tried to make boys and men feel shame for simply being male. And then they are surprised and shocked when men decide to do something else with their time, and their lives.
Men making these choices for themselves is nothing but an overdue logical response. That response is based on awareness, recognition and acknowledgement. That response is causal in men choosing different ways to live, with different lifestyles than the standard one proscribed by the current system. It has caused men to think differently, act differently and see other options.
And right there is part of the anger we've seen the entire time over the last few decades - the knowledge that the choices of MEN would maintain or break the system they had set in place.