ORLY? Two words: Bulky. Water.
And now I will tell you why water types are not overpowered. Simply because bulky water types are just no longer good enough in gen 5. The rise of bulky grass types like ferro, celebi
and offensive ones like Venusaur
means that bulky water types are often a liability and a free switch in to all the mons I mentioned. There are powerful electric sweepers, jolteon
-t which melt water types. If the weather is sunny & with no way to change it, bulky water types are massacred by even fire mons like Volcarona
have all dissappeared and the "bulky" water types that exist are actually multi-purpose water mons capable of filling multiple roles. Gyarados
? Also a DD sweeper. Rotom
-w? Also a good scarfer. Starmie
? Not bulky, a spinner and good sweeper in rain. Politoed
Now the bulky ones, Jellicent
also happens to be a spin blocker, which is the primary reason it is used for. If it was pure water, it would be UU for sure. Same with Tentacruel
. The ability to setup, absorb t-spikes and spin hazards turns it OU. Without its poison typing and toxic spikes, it wouldn't be used at all. (and we are saying poison is bad?) That means the only pure bulky water type is Vaporeon
, used solely for its typing(and wish passing), no frills. We no longer have suicune
, swampert, kingdra
, etc being used much in OU. Nobody puts in grass types or electric types just to counter bulky water types. People however regularly put steel types and ice sharders for dragons. So it would be erronous to say that bulky waters exert much of an influence in OU.