It's unpopular because the fitness crowd is so religious and ignorantly-stuck in anti-intellectualism, but the best strategy to lose weight is to gain as much muscle mass as possible with the less effort to accomplish in order to raise NEAT. It doesn't take a lot of time or effort (mostly dedication and planning) to stimulate muscle development effectively, and becoming a gym rat is essentially wasted time, money, and effort. It's nice to have cardio fitness too, but I would do the minimum to avoid too much IIB to IIA conversion like the anorexic-looking treadmill-only gym users do. If you want no glutes, avoid squats and lifts, and run a lot.