Like everything, it depends on context. Is it good to have separate dev, staging, and production environments? For many companies, the answer is "D'oh!". But if you're one guy trying to get your first p.o.c. out, by all means, deploy directly to production.
Containers is sortof the same thing: if you're a small team, and don't have many customers, the disadvantages of containers (however small) may outweigh the advantages.