How does compromising the divisibility and fungibility of digital cash constitute an improvement? Not that I'd be against a revamp of script, expanding it could allow higher level languages for transactions but that would have the side effect of making the average size of transactions much larger and from that aspect reducing the functionality of script to only a few basic transaction types would actually be more beneficial to Dash.
Blockchains aren't the be all and end all, they do distribution and security exceptionally well but they don't do scale well and trying to cram them full of extra functionality makes that worse. There's an awful lot we could do with chains tailored to different purposes but in many cases they're better suited to providing security for layers built on top to provide the extra functionality, there's not much point trying to stuff gigabytes of data into each block when a hash of that data is just as secure and only needs a fraction of the storage.
That's what the masternodes are for and communications on that level can handle complex transactions far more efficiently than each individual transaction carrying it's own complex instructions and permanently stored on the blockchain, for example you can put any amount of extra complexity in a separate DB verified with a single hash in each block and expire anything obsolete without touching the chain.