I don't think it's Rudess's fault, though. I did for a while - I miss Moore-era DT, and I've always thought Rudess could be replaced with another guitarist and no one would know the difference - but then the "An Evening With..." duets and "Octavarium" kind of changed my mind. His playing is gorgeous on the former, and the extended introduction on the title track of the later is absolutely great, very Pink Floyd.
I've kind of systematically went through the whole band in that regard. It's not Rudess, it's not Petrucci, who's solo disc was awesome, I thought it was LaBrie, but his solo disc from a few years back was great too. No one notices Myung so I'm pretty sure it's not him either. And LTE was really Portnoy's thing, and was also great, so I don't think it's him either.
I just suspect that DT as a band realizes where their bread is buttered, and goes out of their way to write flashy compositions with dozens of tempo and key changes, with extremely technical solos and as many solo sections as they can squeeze in, and puts the songwriting on the back burner. Their solo projects then become a chance for them to actually write songs, which is why I suspect I like most DT solo projects but haven't been able to get into much the band's done in years.