Not to mention that some trademark owners have become downright abusive.
Think about it: the whole purpose of trademark law is to protect both the health and safety of consumers, and the reputations and profitability of legitimate businesses.
Trademarks were developed as a means by which goods from a particular source could be recognized, even if they were widely distributed through any number of middlemen. For example, Oscar Ferdinand Mayer, a German immigrant butcher, became sufficiently renowned for the quality of his sausages and hams, that the demand for them far outstripped what he could personally sell to consumers, so he began putting his name on them, and wholesaling them, eventually marketing them nationwide. Consumers knew that if they saw his name and logo on meat products, they were the products of a reputable company, that had been one of the first voluntary participants in the federal meat inspection program.
But as I said, some trademark owners have become downright abusive. For over a century, toy and model train rolling stock was routinely decorated with the names and logos of real railroads and railroad-related service companies, and nobody had so much as a second thought about it. The railroads considered it free advertising. Some companies, like the Auto Train Corporation (which operated the Auto Train service for its first decade, from 1971 to 1981), were very picky about the logos (and the TM superscripts on them) being reproduced as precisely as possible, but nobody gave the general use of the color scheme and logos a second thought, because the idea that a string of foot-long model cars, pulled by one or two eight-inch-long locomotives, could create either consumer confusion or trademark dilution for a real rail passenger service, was (and still is) downright ludicrous. Yet a few years ago, the Union Pacific Railroad (if I remember right) started demanding that anybody supplying model rolling stock (or decals for modelbuilding use) bearing Union Pacific logos (or the logos of any of the "fallen flag" railroads that the UP had taken over, like Southern Pacific, Western Pacific, or Rio Grande), whether they were a multi-national corporation or a small operation run out of the owner's garage, had to submit samples for compliance inspection (reasonable), and pay exorbitant license fees (not so reasonable). Eventually (and I think the NMRA had a hand in the negotiations), they backed down, realizing that bullying companies that weren't even their competitors was not in their own best interest.
We live in an age of greed.