Learn English – A word to describe someone with the same taste/likes

The word namefellow or name-fellow, although rather obscure, does have exactly the meaning you're after, without the connotation of namesake that both people are named after the same person.

In Tristram of Lyonesse (1882) by the poet A.C. Swinburne, the protagonist travels to Brittany where he meets another knight named Tristram:

But by the sea-banks where at morn their foes
Might find them, lay those knightly name-fellows,
One sick with grief of heart and sleepless, one
With heart of hope triumphant as the sun

Simple is a tricky adjective to apply to people. In several phrases, it can be pejorative and for that reason some people will take it to be an insult regardless of the rest of the context. In particular is simple minded, which means lacking intelligence or good judgment.

In this particular case however, I would suggest the following phrase variations:

• of simple taste
• of simpler tastes
• s/he is a wo/man of simple taste

In particular, saying something like:

On the one hand, we have gourmets who insist on the best of everything. On the other, are those of simpler tastes who are satisfied with the brands for the rest of us.

... makes it fairly clear that you are drawing a comparison in behavior without passing judgment on the quality of the people involved. Simple tastes may have been pejorative in the past, but in modern usage it is usually said as a point of pride. I think this transformation is in part due to the quote variously attributed to Oscar Wilde and Winston Churchill:

I am a man of simple tastes: I am always satisfied with the best.

Other phrases you could slip into similar comparisons, but which I think are more easily taken to offense:

• economical eater (or buyer) - clear that the motivation for the 'simpler' tastes is not the taste itself. This could be taken as pejorative in a different direction if thought to imply that the subject is impoverished.
• undiscerning - antonym of discerning, which is a high-brow, non-pejorative way of saying picky.
• perfunctory - draws the comparison that your 2nd group simply doesn't put the same effort into their food.
• blissfully ignorant (of the gourmet) - makes it clear that your 2nd group is no less satisfied with their choices, regardless of what judgment the reader or the gourmets may pass on them.

But the bottom line is, people can and do take offense at anything. If you want to avoid any appearance of putting anyone down, you should do as Oldcat suggests and stick to classifying inanimate objects.

The trouble, I think, stems from a secondary meaning of gourmet. The primary definition of a gourmet is a noun, describing a person with good taste in food. This is still the subjective good, in that a gourmet can maintain their own preferences in food. In other words, a gourmet is someone who has the ability to make fine distinctions in the taste of food and drink.

The secondary meaning of gourmet is the adjective form, which implies a standard of quality that has to be met. However, this implies that certain foods, kitchens, eaters etc. are either gourmet or not based on how well they meet this standard. This meaning has made catapulted to prominence due to the pervasiveness of marketing. The implication it carries has created an objective standard. This has caused the whole conundrum of your question. In this sense of the word, being called not-gourmet is an insult; it's saying someone has bad taste in food, prefers inexpensive or bland meals, or can't taste the difference between a box wine and Dom Pérignon.

Therefore, I would propose taking your initial description in a different direction, you could classify your 1st group as food enthusiasts. This term has none of the objective/subjective baggage and simply means that they are interested in and motivated to learn about food.

It can still be a tricky term to find an antonym for, however. The best antonym for enthusiasm is apathy, which has a fair degree of negative connotation. Food apathist (strange there isn't a real coinage for this) or apathetic eater don't ring particularly positive for me. Other terms you could use are:

• Indifferent
• Disinterested
• Egalitarian - purports the belief that food is food, regardless of how it tastes; as long as it keeps you alive, it's good. See soylent for an extreme example of this.
• Agnostic - similar to egalitarian, it has the following definition

2. a person who denies or doubts the possibility of ultimate knowledge in some area of study.

Which would make a food agnostic someone who does not believe in the absolute quality of one food over another. Also see: Hunger is the best spice.

On a related (sarcastic) note, I would contend that any true Gourmet would not be satisfied with any pre-made pasta sauce. Further, I contend that anyone who has ever made a fresh ragù from scratch would agree with me.

Dropping the sarcasm, I personally love to cook and eat a meal that requires hours of preparation and monitoring (I have it on good authority that a real ragù has to be simmered at least 3 hours to cross the threshold from a pomodoro sauce), but I rarely have the time to do everything I want. Most of the time, I'm cooking for speed, and if that means having Kraft dinner, I don't lose any sleep over it; in fact, I'm just as happy on those occasions.