I don't see any reason the business model shouldn't exist, though yes their scale was a challenge IMO.
Selling off the shelf, tested components and themes isn't a bad business. I'd firmly put it in the lifestyle business category, I just wouldn't expect it to sustain multiple high paid engineers on fulltime salary and benefits.
A relatively popular WordPress theme on ThemeForest in the market's prime could bring in $30k on a good month. Nowadays the number is much more humble.