There are reasonable criticisms of Systemtap, but a lot of Sun marketing was just bizarre. They set it up on Ubuntu (which doesn't include it, and which isn't their competitor: Red Hat is) as an example of what the setup is like. They kept complaining it was unsafe, when it was only unsafe if you wanted to use raw C for tapsets. Sun had some great tech, but they were also a sales and marketing machine that had no problems spouting garbage to make a sale.