Malicious transactions are possible on the Bitcoin network. This has been known for years. It's not a valid argument for keeping the blocksize back in the Stone Age.
Returning to the topic at hand, has anyone looked at this chart lately?
https://blockchain.info/charts/transaction-fees?timespan=all&daysAverageString=7Seven day average of total transaction fees. We're at roughly 120BTC per day in fees right now. That's no small potatoes.
The threat of malicious transactions is one of many valid reasons to keep max_blocksize compatible with a diffuse/diverse/defensible/resilient (ie decentralized) network.
Gavin explained why, in perfectly clear English.
120BTC per day in fees is great news.
That will help fee markets develop and is a sign Bitcoin is starting to work as it was designed to.