This is true; however, a beginner shouldn't go to the other extreme, either -- that is, it's best to stick with just a couple of films (one fast and one slow) when starting out. Trying everything in sight to find the one that's best can lead a beginner in the darkroom to get a very poor feel for how things work, because the constant changes in film will make it hard to fine-tune development times and otherwise learn about the effects of important variables. Furthermore, if you try a bunch of films, the starting point development times are likely to result in different densities from one roll to the next. Thus, you can't really be sure that what you like about the film you choose really is the film, as opposed to the development time. These different densities will also require different paper grades and exposures when printing, which will complicate learning to print. Finally, to a beginner, the differences between different films are likely to seem pretty small compared to other factors, such as contrast and exposure when making prints. It's going to take a while to get decent control of such things, and only then will the differences between films become apparent.
Overall, then, I'd say a beginner should go ahead and buy several rolls of whatever film seems good based on price, availability, or the recommendation of friends. Perhaps an entire bulk roll would be too much, though; I think most people will begin to appreciate film-specific factors well before getting to the end of a bulk roll, and if a film is a bad match to the photographer's needs, the issues you mention will then become important.