On the other hand many third rail political views have a great deal of popular support. So, IMO the trick is to require a very large number of signatures to get on the ballot.
In Washington State, the initiatives frequently yield legislation that has conflicts/dependency problems with the existing law, something that happens far less-often with bills from within the legislature.
Also agreed that a high signature-number bar is one of the simplest/expedient ways to limit ballot-initiative spam. We have a person who has successfully made it their personal mission/job/source-of-notoriety to place some sort of small-government initiative on the ballot every year.
Neither does the legislature, in many cases. On balance I'd rather have direct democracy for the majority of things. It has worked quite well in Oregon, which has an initiative system.
Oregon passed something similar, albeit weaker; I wish we'd passed something much stronger. Not because I'm anti-taxation, but because funding anything via property taxes is an incredibly bad idea and leads to funding and service quality that's correlated with property values.
If you're going to change property taxes that much, though, you might as well go all the way to a land-value tax, which would also reduce problems with assessment and improvement.