Well that's more the fault of the person not having willpower and drive than the concept of weightlifting. I changed my lifestyle cold turkey and I've been at it for over a year and a half, with a break in between only because I had to have surgery lol.
And people that lift don't "guzzle protein shakes" they use them to supplement their protein macros for the day. Don't be ignant, jussaiyan.
Building muscle IS healthy, regardless of if you do it in a gym or with your body weight. Like I said, it improves quality of life to actually have strength.
Statistically speaking, it is way more common for someone to change their routine/diet cold turkey and fail, than it is for them to be successful and maintain that.
But I didn't state it's true for everyone. You obviously had the willpower and know how a protein shake is used. Most people do not. Don't confuse my assesment of the many, to extend to the few.
I'm sure you know exacly the type of people I'm referring to. Th ones that see you and say "hey you look good, what do you do to stay in shape" you let them know and hen next thing you know they are up at 5:00am going running, protein shakes, over extending themselves at the gym for 3hrs a day, have more protein shakes, rinse and repeat until they quit and tell you it was to hard.
Those are the people I am referring to:)
Edit: And for the record, I'm not saying it cannot be done, but doing it this way is a high burnout rate.
If you want to be healthy, set a weight loss goal, and get a workout routine that works for you and be diligent about it.