Passion is difficult to measure, perceived passion in other people even more so. I advise to not make your career decisions based on what other people are doing or how you think other people feel.
Also, IMO passion is not necessarily a good guide for what you can successfully turn into a career. For one, passion doesn't necessarily come before a degree or career - it may come after. Second, a lot of people have passion for things that just cannot be easily turned into a career. Save your passions for your hobbies; pick a career based on what you are good at or what can earn you a livelihood. If you are good at it, you will probably eventually develop some passion for it, or at least some aspects of it. For instance, you may be good at chemistry, but have no "passion" (whatever that means). Still, you can get a job in chemistry industry and find eventually that have a passion for certain other aspects of your job that have nothing to do with chemistry, per se, like writing or people management. So now you are in a job doing something you love that just happens to have a chemistry basis. I also note that passion for a subject depends on what kind of teachers you have had.
Basically, if you feel you are pretty good at chemistry, there's no reason to stop just because you don't dream about molecular bonds at night. Plenty of career opportunity under the heading "chemistry" where you can scratch your other itches.
Ultimately the decision whether to get an MS or not depends on where you want to go in a career. I want to be clear that people who hold a BS and have been in the business a long time are no more or less knowledgeable or useful than chemists who get a PhD. I know plenty of BS level chemists who are incredibly talented at what they do, have very deep knowledge, and are valued members of the team. The biggest career difference is that there are barriers to BS holders to get into upper management. Not impossible, but more difficult. BS chemists tend to specialize in a few techniques and do more routine daily work. In later careers, therefore, their knowledge tends to be very deep, very practical, but also pretty narrow. My perception is that their jobs tend to be lower stress because they have fewer long-range responsibilities outside doing their important daily work proficiently. Contrast to higher degree holders, to some extent MS holders and definitely PhDs, who are trained to manage large research projects and therefore tend to be exposed to more techniques. They do not tend to do the same task every day. In later career they tend to be less involved in benchwork and more toward project management and decision-making. Their chemistry knowledge tends to be broader, more theoretical, less practical. Because their responsibilities are more long-ranging and complex, they frequently take their work home with them, in either actuality or "in their head". I am speaking in generalities, of course. The spectrum of careers is too complex to summarize in one paragraph.
All things being equal, in this day and age my view is that the general benefits of a masters make it a good option for most people who are interested in a career in chemistry. For a long time MS degrees in chemistry didn't really exist, and were mostly awarded to people who couldn't complete PhD programs. In that sense, they had a little bit of a stigma. This isn't the case at all any more and now many Universities offer dedicated masters degrees in Chemistry. Masters holders in chemistry are attractive to industry because these degrees signify some advanced skills, additional coursework, and particularly are taken as a sign of training in important skills like managing a research project, independent thinking, problem solving, etc. For a minimum of extra time in school, MS holders will enjoy an advantage when applying for better paying industry and government jobs. The extra year or two also will afford you a chance to be exposed to more advanced coursework and skills, which will help you decide if that "passion" exists for the subject.
Obviously if you come out of a BS with no interest at all in chemistry and prefer to explore other professional programs (medical school, dental school) or simply want to get a good chemistry industry job with few long-range responsibilities outside the 9-to-5, if you have no interest in management (of people, of budgets, or of projects), then there is no reason to get an MS. Some people just want to get on the job market without more school. Perfectly valid option - you can always get a masters later. But just be aware that although "get another degree later" is an option, in practice it can be difficult once job, family, etc. aspect of life get momentum.
I guess my advice if you are unsure, and are willing to spend the $$, my advice is to get the MS and do so now rather than later. That's based on no knowledge of the nuances of your situation of course. In few cases will having a MS hurt you.
Well that's some random musings. Hope it is helpful in some way.