That's not the issue here. The issue is that YT is (arguably) using illegal measures to enforce their own rights. Just because someone infringes on your rights doesn't make it legal for you to infringe back on theirs.
That they offer an ad-supported service does not entitle us to an ad-free service.
Limiting playback without ads is not beyond the rights of the information service provider.
In other words, the issue is not that YT fights back, it's how they do it.
Are you familiar with keggerator systems with usage quotas? ("Free as in beer")
How can a computerized keggerator system (or a bartender) limit a person to a specific number of drafts from the tap? Is that spyware, or what you agree to when you draw from their kegs?