PFS suites suffer from the same defects as any other salt-less password hashing scheme.
Why is everyone promoting Perfect Forward Secrecy (PFS) ciphersuites so fiercely?
Namely, when the group/hash weakens, then the attacker can invests into a massive pre-computation, after which individual connections/hashes can be broken with minimal additional cost. This property allows the big players to amortize the cost of the massive pre-computation over the massive ammount of cracked connections. Consequentially, it promotes mass snooping over targetted attacks.
This question is motivated by the WeakDH/LogJam paper.
EDIT, thanks @steffen-ullrich, It does not make sense to include the salt in "the secret", so the DHE equivalent of salt-less is "everyone uses the (few) same groups".