The cost of attending the worlds is pretty extreme, easpcially if one doesn't live in the host country. And if a manufacturer is going to send a whole team, then that extreme cost becomes even more so. Perhaps even more problematic, at least for the 1/12th scale worlds, it has become almost common place for one or two of the teams to bring very special tires that are only made available to their own team drivers and for those exclusive tires to yield a distinct performance advantage. Whether said tire advantage is actually true or not is not so much the point because the general perception is often that the 1/12th scale worlds have often been won by those who have exclusive access to superior performing tires, while the rest of the field has little chance of overcoming the winner's clear tire advantage. So it is not all that hard to understand why individuals and/or companies have been tending to shy away from making the huge investment required to participate in the world championships only to find upon arrival that there is yet another special must have tire that is unavailable to them. It makes perfect sense that the major nitro races and also the electric sedans are typically run on spec tires, often with strict limits on the number of sets that each participant can use during the event. Such tire control rules eliminate even the perception that the major races are being won by those with exclusive access to superior tires. It is likely that interest in and participation at future 1/12th scale worlds will continue to wain until such time as the longstanding tradition of tire controversy is eliminated by the simple adoption of tire control rules, comparable to what is already being done for most every other form of RC racing championship event.