AS Pellegrim said, mainly non-tournament players complaining about frequent changes.
The freeze was welcomed by tournament players, but mostly of those books Pellegrim marked as broken, namely OK, WDG, BH... I would probably go with SA in this bunch, but he has the data.
Competitive players with books off-balance after 1.2 and 1.3 feel that their books needed a few more tweaks before freezing, as well as nerfs to the four noted.
The truth is that most books are externally in a decent balance, but to some, this comes with a price in terms of internal balance, or simply a number of different competitive play styles.
Again, we might be wrong, and I would be more than happy to admit it, as it would mean we got a better thing than I thought we did.
Anyway, stability is something we all asked for, we just hoped for 1.4 to be it.