CMU has 6300 undergrads (and an equal number of grad students who, except for those who were CMU undergrads, will never care about buggy). So we have 4% of the eligible students, which sounds like a lot. But peak buggy was 1988 with 72 entries, and it stayed above 60 for much of the 90's. So almost 10% of the (then smaller) university.
Stronger teams are good, but we need more teams. Each team pulls from a different recruiting pool - the independents each appeal to a different kind of person, and PiKA takes different pledges than PhiDelt does. It may be that everyone who seriously wants to participate in buggy has already found a team. But there's all the people who want to do something (buggy/booth/whatever) and happen to land in buggy because the rest of their social group does it. E.g. the Greeks who don't particularly love buggy, but show up to fill out a push team because their more buggy-serious brothers persuaded them. Where do the freshmen who would've pledged KDR go now? A non-buggy house? Or not Greek at all? Either way, they're a demographic that is lost to buggy.
The membership requirements came about to prevent a strong Greek team from getting even stronger. That's not the main concern now, so, sure, allow free choice of pushers for everyone and if it creates a monster, deal with it then. It only requires convincing one independent that it's in their interest to vote for the rule change next year. But would the Greek alumni really be happy when a Greek team wins with a lineup that includes no Greeks?
It used to be that Greeks could get $1000 for their buggy programs with no strings, I don't know if that's changed - certainly funding for independents was tighter when I last paid attention than it is now. Parity would require the student senate to change their policies, but I would think the Greeks have sufficient pull there. But for full parity, Greek buggy programs should be subject to all the same strings that the independents are, which might have undesired consequences - the Fishing Club can't refuse anyone who shows up wanting to be a mechanic. Though nobody seems to use that trick to get into independent buggy rooms.
So we have PhiKap, DTD, DU, and Beta as ex-powerhouse teams with alumni who remember their glory days. Are open rosters, funding, and a starter buggy enough to lure them back into the field?
The teams that put in the bare minimum qualifying effort this year drove reasonably well - SigEp's mechanical failures wouldn't have been prevented by giving their drivers more practice. Despite the lack of practice days last spring, 2015 wouldn't have had a unusual number of crashes if not for the wet roads. To me, that says the last-minute teams are getting in enough practice for the speeds they go. Maybe they could get by with even less. More practice helps the serious teams get faster, which is why it is worth the effort to them to get up for every practice. But a small team that can't round up enough bodies for a day misses out and never gets to catch up. Every freeroll practice costs money and effort (from everyone) regardless of how many teams show up. Fewer practices would lower the difference between least & most experienced driver. If they knew they'd have to race with little practice, serious teams might make different design decisions, or learn how to make the most of the practice they get.
Wheel escalation is a good way to transfer money from teams to vendors' pockets, but it is an area of useful innovation, without which buggy becomes boring. $600 to ZE seems a fair cost to step up to the fast table, especially considering that the (unpaid) labor that goes into building a buggy is an order of magnitude larger and the difference between best & worst buggies is smaller than between the best & worst wheels.