It is one thing to have the ability to potentially end a combat with a single attack, and actually have the confidence to do it.
This sounds a bit like
psychofeedback, which is nearly universally hated on the WotC Psionics Forum. Virtually every DM nerfs it.
Firstly, given a large number of creatures, some are likely to make the save, even given a bad Will save.
Mind Blast has the save DC of a 4th-level power (and quite simply one of the best
5th-level psionic powers out there), and you can pull it off at 4th-level. I still have a problem with this.
(In fact, Bruce Cordell nerfed it somewhat in Mindscapes. It's still 5th-level, but it doesn't stun the opponent as long, and it no longer penetrates PR IIRC.)
4 psionic power points, with a 4th level Egoist. What are you going to do? Claws of the Bear? Do you really want to get up close and personal with your number of hitpoints?
I think the design of the egoist needs another thread

Besides, Mind Blasting sounds quite telepathic to me. There's no reason to turn every psion into a telepath.
Now the chances may not be very high, and your DM may be very generous, but sooner or later, you are going to get attacked by a group of them. The DM, has after all allowed psionics in his campaign. Each defense costs power points. Once you are out of power points, you are into stat loss territory, which is hard to repair for low level characters.
What really makes Psionic combat suck is that psions (the ones you want to affect with your psionic attacks) have good Will saves that scale with level, while your attacks DC's do not! Most wizards do not try to roast the rogue with a fireball. Thus the expenditure in comparisson to the potential for damage is VERY weak. But the DM does not need to worry about this, nor do monsters expend power points to attack or defend!!!
I agree that it sucks. You're never going to use it to attack, and you either have to waste power points on defense modes or suffer stat damage for days.
However I'm surprised that you mentioned a psionic monster's power point usage (or lack of usage) as a problem. A psionic monster still has to waste a standard action using an attack mode (except Mind Blast, which is actually useful). [Sure, it hoses the player character, but it almost never actually knocks them right out or prevents them from manifesting a psionic power immediately afterwards. It's bad tactics, and a waste of a standard action.] The psionic being has no way of determing it's opponent's power point score (indeed, it usually can't determine who is psionic and who isn't), and it would be better off using Brain Lock, Mass Concussion or whatever other
free powers it has, physical attacks (also free), or whatever other (useful) options it has (usually free).
The only exception is the brain mole, whose sole purpose is to hose psionic opponents (if they can figure out who is psionic, since Detect Psionics takes three rounds to do anything).
Even unintelligent creatures are governed by natural selection. An udoroot that constantly used an attack mode is going to suffer, whereas one that uses
biocurrent is actually going to do something useful in combat and enjoy crispy fried humans in it's fertilizer.
Frankly, I think a DM who is using an attack mode (except Mind Blast) is engaging in meta-gaming and unfairly targeting the player character while using bad tactics - or they're as bad at math as I am, and they're still using bad tactics.