Of course, the advantage of honing technique in a correct way (which is not with a compliant uke, but more a form of ippon kumite) over cultivating "fighting spirit" by sparring, becomes visible after many years.
I mean that in two distinct ways. Firstly, it takes many years to get good enough to get the pressure points, locks, minimalistic tai sabaki, et cetera right from the first time. Secondly, you can probably still defend yourself with this type of discipline once you're 75. The average thaiboxer, to name just one sparring based art, will be far more lethal after his first year than a student of ninpo tai jutsu ( Thai jutsu versus tai jutsu, interesting wordplay), however, I doubt many competitive thaiboxers will still be able to use their experience to the fullest once they are, let's say: 75. No doubt there are exceptions on both accounts, but i think the general trend is as such. Regardless, I would have to agree that at least at a certain point in ones martial art training, pressure training becomes much desired, the form in which it comes may vary though. I like to put students in situations reenacting real situations, some form of roleplay if you wish. It takes a good "uke" to do that though, verbally taunting, prodding and pushing to check control and composure. It's more of a mental training, but it shows how many people simply mess up by (for example) responding ineffectively and with poor timing after the slightest taunt, thus acting in favor of the attacker (who's trying to get some response to justify excessive violence or whatever). Others simply freeze and sob, not the way to go either, and others still get nervous and fail to execute any technique properly at all. It's an intermediate form of pressure training, but if applied with some spirit, it can be productive. Most self defense fights don't last 8 rounds anyway, it's all about initial response and composure in my experience.
(of course, this being said, sparring is simply alot of fun, but not all disciplines are equally suited for it.)
just my humble 2 cents worth of oppinion.